 Let's turn the clock back a few years to Katrina, that horrendous storm that struck New Orleans. It stopped nearly everything – power stations, internet services, mobile phones – but one service held up. There was one way people could be informed about what was happening. It was radio broadcasting. When there is a disaster, the authorities need to use every single means they can to tell the public what's happening and what they should do. Television, email, social media, amateur radio, satellite – every service can help, but the service that is least likely to fail to get through is often radio broadcasting. At these times, mobile phone networks and internet are stretched and overloaded, and in fact they are desperately needed by the emergency services themselves who need priority access. Radio mains power in the home can mean no television and no satellite receiver. Radio is everywhere in the home and car. It often working from a battery. It wins in terms of ease of use, reliability and cost. It never runs out, however many people tune in. It provides the maximum reach at the fastest possible speed. So radio should be the cornerstone of emergency services. Whatever more sophisticated services are available as well. And radio can go further than just a voice. All radio systems, analog and digital also have the potential to provide text as well as audio. In principle, radio could provide all kinds of written information about the disaster as well as audio. The text can help the hearing impaired. It's also possible to wake up the radio if it's switched off. And for this to happen, we need more sophisticated radios with small screens as normal and smartphones and tablets to be radio capable. Wouldn't that be something great? So when we talk about radio in times of emergency and disaster, there's one word that describes its role. And that word is indispensable.