 three men enter a room to clear an obstruction in an industrial facility. It is the 5th of February 1989. Not long after working in the area they begin to experience headaches and feel ill. The men are working in an industrial irradiation facility just outside San Salvador and they are experiencing the first symptoms of acute radiation sickness. Within six months the three men would undergo multiple surgeries which would result in amputations, skin grafts and for one of the unlucky trio death. The event may sound familiar you might think but this accident was the ignored warning which led to the Sarek radiation event just one year later the San Salvador radiation event. Irradiation facilities are an important tool for the sterilization of a multitude of different products including the food and medical industries and today's story we'll be talking about the latter. You see most countries have some sort of radiation facilities be it commercially or government owned and El Salvador was no different. One such facility was built in 1974 being commissioned in 1975 based near the country's capital city San Salvador. It was commissioned and owned by a Mexican Salvadorian Costa Rican consortium the facility housed a model JS6300 gamma sterilizer designed built and supplied by atomic energy of Canada limited and those of you who have been taking notes during my videos will know this company has come up a few times before. As part of the installation process three staff were trained by the Canadian company in how to properly operate the machine. This model of a radiation device makes use of a rack for multiple pencils of which contain radioactive source elements in this case the gamma ray emitting cobalt 60. At the time of installation the total reactivity was four petobeccules but this reduces over time necessitating semi regular replacement to ensure reasonable irradiation times. This is held in place by a hoist and guide cables. When not being used for irradiation duties the rack is lowered into a water pool for shielding by pneumatic hoist working the hoist cable. The whole irradiation machine is housed inside a concrete shielded room accessible via an area called the maze protected by an interlocked door. The radiation room door can be opened from the inside so that personnel cannot be locked in. An emergency poolway cable was also provided mounted along the walls of the radiation room and the entrance maze. This actuates a stop switch that lowers the source or stops the startup operation. Materials to be irradiated are usually placed in cardboard or fiberglass boxes. These containers are then themselves placed on a metal tray. Pneumatic pistons push the boxes along a set path over two levels each time exposing a side of the box to the source. The path the boxes take results in 29 irradiation positions and the time in each position was around 2020 minutes. During an irradiation cycle access to the room has to be restricted because of the high risk of exposure to the Cobalt 60. The irradiation room had a number of controls to prevent A access to the room when the source is out of the pool and B the source being raised when someone is in the room. This was designed into the system by AEC Limited and a vital part of this was the machine key. This was used to open the irradiation room door, operate the control panel and actuate a time delay switch inside the room and only one key was used as an extra method to prevent activation of the irradiator when the room was accessed. To enter the room the operator must go to a monitor test panel next door. There they would have to initiate a monitor test by pushing the appropriate button. This will take reading of the radiation levels in the room by using a sensor probe installed near the irradiation machine. But once the button is released the probe must again be able to read background radiation levels before releasing the interlock allowing the door to be opened. On top of the hardware and force safety proper administrative controls are also meant to be used. This also ties back to the important machine key and on this key a radiation monitor is meant to be attached. This is meant to make sure that upon entry to the room at least one method of dose rate monitoring is provided. This is meant to be calibrated before any entry on a known low radioactive source within the door frame of the entry door. Now as the basics of how the operation was meant to happen let's return to reality starting in 1975 as multiple levels of safety controls would break down and be forgotten over the following years. Not long after operation had commenced the facility would experience its first incident. In 1975 facility experienced a product jam and product boxes obstructing the movement of the source rack. This caused the rack to deform allowing the pencils to fall out. But a staff on site who had been trained by Atomic Energy of Canada Limited dealt with the incident with no major issues. In response the supplier investigated the issue with the machine and repaired it accordingly. The facility would change hands later on in 1975 when it was sold to a consortium in the United States of America and during the change of ownership the originally trained staff would be let go. This resulted in new staff being trained verbally and not from the original equipment supplier. The facility like many other establishments in the country at the time would fall victim to the El Salvador Civil War. Beginning on the 15th of October 1979 the conflict would run for over 12 years and as such the facility fell into disrepair as economic hardships gripped the country. Because it was feared the facility may become a target in the civil war nothing on site was written down and even the location of the plant was not made public knowledge. The owners were fearful of allowing officials from the government on site and any new employees were told as little as possible including the dangers of the materials used by the machinery. The source needed to be replenished by the beginning of the 1980s. This was due to the natural decay of the Cobalt 60 but costs meant it was left as it was. Eventually in 1981 the owner of the plant reached an agreement with the supplier for replenishment of the source. A representative travelled to San Salvador only to turn back at the airport due to the escalating civil war. Another side effect of the civil war was the lack of safety inspections from the supplier. All of this led to a gradual misunderstanding of the equipment safety features as staff trained new staff verbally resulting in variations way beyond what the original supplier would have given. Another component was that governmental radiological administration was also lacking. Understandable due to the political issues at the time but this would result in regulatory legislation being non-existent. The situation wouldn't get much better throughout the 1980s with the facility making do and mending the machinery including modifications that the manufacturer would never have approved of. The lack of maintenance resulted in the vital monitor probe failing. In order to keep using the radiator it was removed but you might wonder how the operators would gain access to the radiation room. What a neat little trick was discovered. Access could be gained to the room by depressing the monitor switch and repeatedly cycling the buttons on the panel of the radiation monitor. This method became the usual procedure gaining access to the radiation room even when the rack was in a deadly up position. Regardless of the now non-working interlock the access door had become badly fitted due to lack of maintenance which resulted in it being openable by force or by using the blade of a knife to slip the catch. And this leads us to February 1989 and a series of events that would lead to an exposed source not being discovered for six days. It is Saturday the 4th of February 1989 and one of the operators starts his night shift. As was the norm for the facility he had to deal with a number of power failures and problems with the pistons but after some wrangling he managed to restart operation each time. At about 2 a.m on Sunday the 5th of February during a much needed coffee break a fault occurred which caused the source rack to be lowered automatically from the irradiation position. Needless to say this would be a problem. Lowering the source caused an alarm to sound that indicated that the rack was neither up nor down. The operator returning from his break heard the alarm and promptly went to the control panel to try and perform the reset procedure but this failed. The next step in the operator's repertoire was to leave the building go outside and climb onto the roof to try and force the source hoist down. This was done by detaching the normal regulated pressurized air supply and applying an over pressurized supply. This was to force the source into the fully raised position hoping that this would free the rack and permit its descent into the storage position. This non-manufacturer recommended procedure also didn't work. The alarm continued and in order to trick the system the operator pulled on the cable until it left the hoist mechanism. After this he fed it back down which activated the micro switch telling the system the source was down. The operator returned to the control panel. He found that the red general failure light and source up light were still on. He went back to the roof and managed to manipulate the micro switch so that upon returning to the control panel the green source light down was now on. To gain access to the room the operator now performed the other non-standard procedure which ever since the monitor probe had been removed a few years before meant that access to the irradiation room was achieved by rapidly cycling the buttons on the radiation monitor panel while turning the key in the door switch. This simulated background radiation readings thus allowing the radiation room to be entered even though the source rack was in the up position. The operator knew the rack was in the up position but it seems like he was not aware the dangers this posed as his next move was to cut power to the radiation machine and enter the room. He did not check the radiation level once he reached the machine and guided by torchlight only he started removing product boxes gradually working his way closer to the source rack. Near the source rack he found five boxes jammed into the space of four. He removed two of the boxes one of which was wedged against the lower of the two source modules in the rack. This took several minutes leading to an extended exposure time unable to fully clear the machine he left the room restore power and sought out assistance from some of his colleagues. The operator returned shortly after with two assisting members of staff. The trio now sought out to re-enter the room at around three in the morning. The two staff members roped into assisting the operator had no training in radiation and the irradiation machine. The operator assured his helpers that the machine was safe if the power was switched off. The three men entered the radiation room and started to remove product boxes from the third row on the upper level next to the source so that the rack could be freed from above. In order to free the source rack it needed to be lifted. The rack which was around 60 kilograms needed all three for the effort. Standing on the upper level product tray one of the men pulled the hoist cable. The other two lifted the source rack. After being freed the rack was then lowered into the pool. The men were surprised at the chairing cove glow that greeted them. The operator seeing this as something to be worried about hurried the men to leave the room. Clearly by now he had realised there was indeed some kind of hazard. Not long later the operator started to feel dizziness and nausea. Classic initial symptoms of acute radiation sickness. The trio went outside the building to sit down and the operator continued to feel increasingly ill. At about 3.30 in the morning he began to vomit blood and two of the men went via taxi to seek medical help. The men made it to the emergency room of the Primero de Mayo Hospital. Upon arrival the other worker began to feel ill at the same time and the third worker who by now had returned to his original working post also began to feel ill and he also went to hospital. The company was not made aware of the accident and instead had put the absent workers down to a sick note exclaiming that they had food poisoning. At around 6 o'clock in the morning a new worker booked on for duty. He was confronted by the mess of the night shift. He straightened the boxes and started up the facility. When the first operator did not return for his next shift this worker remained and operated the facility for another shift. But this day one exposure event wouldn't be the last of this old deal but we'll have to come back to that in a little bit. By now all three of the original exposed men were vomiting. The men were misdiagnosed with food poisoning and given three day sick leave certificates and were discharged at about 6 o'clock in the morning the same morning they had attended at the hospital. The first operator would return to hospital on Tuesday the 7th of February with nausea and vomiting and also burns on his legs and feet. After he explained to the doctors of the events of the Sunday he was diagnosed with radiation burns from acute exposure to cobalt. His symptoms were treated but his condition continued to worsen. The decision was made to transport the patient to another hospital for more specialized treatment. He arrived at the Angeles Dell Pedrigo Hospital in Mexico City on day 24 post exposure Tuesday the 28th of February. He had lost 20% of his body weight but would make gradual improvements over the next 100 or so days. The amputation of his left leg looked likely as well as a high probability of him developing leukemia. By day 173 Thursday the 27th of July his condition was considered to have improved enough for him to be returned back to San Salvador but his condition would continue to deteriorate. On day 197 after multiple surgeries damaged to his lungs and a progressively worsening condition he passed away on Sunday the 20th of August 1989. The other two exposed workers would fare a bit better due to them only being in the radiation room once. The second patient who went to the hospital the operator returned to work four days post exposure but was sent home due to his poor health. He again returned to work on day nine post exposure Monday the 13th of February but was unable to lift heavy objects. With discomfort in his feet he returned to hospital where he was then admitted for radiation exposure. Like the operator he was two sent to Mexico City for treatment where he would have his left leg amputated due to necrosis. He returned to San Salvador on day 173 where he would then have his right leg amputated but luckily for him from there his condition improved. The third victim was the least exposed at the three. He was two transferred to Mexico City but spent less time there receiving treatment for ARS. Upon returning to San Salvador he had main off work sick until day 199 post exposure or Tuesday the 22nd of August 1989. The operators mean body dose was 8.1 grey. For reference five grey as a whole body dose can be lethal and he had more than that with his torso receiving an estimated 10. The other two men received 3.7 and 2.9 grey respectively. Back to the aftermath of the exposure after the first operator never returned to work on Monday evening. Well the company just kind of carried on as normal. What the operators didn't know was that the source rack had been bent and it was only a matter of time until another incident which would come on the Wednesday after the initial incident where the rack became jammed again but this time it was released by the over pressure trick. Thursday the 9th day five after initial exposure some of the source pencils escaped the rack and fell into the pool and the irradiation room. This was discovered on Friday day six post exposure after quality assurance discovered the products had been irradiated less than normal. All workers would enter the room after checking the dose rate on a beeper style detector just outside the door which was essentially a pointless endeavour as the dose rate outside the room would have been 30 times lower than inside. Upon entering they were exposed to one of the pencils which had escaped the rack but their exposure was low ranging from 0.22 to 0.09 but this could have been far worse if more pencils had escaped. This now left a massive headache for the owners how to make the irradiation equipment safe and secure this forced management to finally request the supplier's assistance. Two experts from the supplier arrived at the plant on day nine Monday the 13th of February. They succeeded in determining by means of a remote television camera and an iron chamber device sent into the irradiation room attached to a product carrier that there was an active source pencil on the upper level. They drilled a hole in the roof of the irradiation room and on day 11 Wednesday the 15th of February using a remotely controlled tool succeeded in picking up the pencil successfully lowering it into the pool. At 1930 on the same day the experts confirmed that the radiation in the irradiation room was at normal background levels. Due to the poor status of facility the supplier disabled the machine and a full count of the source pencils was photographically undertaken and confirmed all were in the pool in November 1989. The incident was caused by a jam of the fiberglass boxes. By 1989 many of these containers had become cracked resulting in a higher chance of getting caught within the machine. The boxes were forced against a thin steel bar in the frame in which the source rack is raised and lowered. The deformation of this bar was enough to cause the source rack to become stuck in the raised position. The main issue of the incident was down to the actions of the staff on the day. If the product jam had happened just after the facility had been opened it is likely the issue would have been dealt with safely but two decades of neglect and poor training resulted in the dangerous actions of the staff at the facility. The operation of the facility safely was greatly hindered by the political and financial situation in the country as the supplier did not have the ability to send out the staff to inspect the plant due to safety concerns. The plant was refitted with a new radiator in the early 90s and subsequently had its safety procedures and safety systems overhauled. This video is a plain difficult production all videos on the channel are creative comments attribution share alike licensed plain difficult videos are produced by me john in a currently dark and cold south-eastern corner of london uk help channel grow by liking commenting and subscribing check out my twitter for all sorts of photos and odds as sods as well as hints on future videos i've got patreon and youtube membership as well so if you fancy checking them out please do and all that's left to say is thank you for watching