Twitter Alerts, which gets messages to users via SMS and push notifications, was successfully rolled out in the US, Japan and Korea in September.
Now the increasingly influential US social media company has partnered with 57 UK organisations, including all of the police forces, London’s emergency services and the British Red Cross.
This ability to reach people quickly and directly is crucial in a large-scale emergency, says London Fire Brigade comms officer Ashley Fryer.
"If we need to tell Londoners something very serious, we can communicate it instantly to a lot of people," she said. "The message will be pushed to people’s phones unlike ordinary tweets, which must be actively shared."
The British Red Cross is involved because it has an officially designated role in times of national emergency to provide support to the police, fire and ambulance services. It was deployed during the London bombings in 2005 and in major floods in recent years.
Its use of the Alerts service will be reserved for national scale emergencies, according to its head of external relations Adrian Thomas.
Each organisation has to decide in which circumstances to use the service and who is responsible for producing alerts.
Thomas says: "They will be managed by our social media manager in the external relations team but very closely integrated with the messaging provided by our emergency support colleagues and their partners in the blue light services."
Anna Macarthur, London Ambulance’s head of comms, says its comms and social media team will work with operational colleagues to decide on the situations in which it might be used.For the London Fire Brigade, the service increases its ability to act like a news service and work around, as well as with, the media.
"We already use our Twitter feed to report on serious, high profile, and unusual incidents happening in London, and we find journalists will often pick up stories from our tweets," says Fryer.
"The main difference with Twitter Alerts is that we will be the initial source of news that goes directly to people’s phones. That’s important for us as it means we can confirm things officially, rather than waiting for second hand, unconfirmed reports through normal news channels."The fire brigade is not the only organisation prioritising digital for lifesaving situations, with the Red Cross launching a free mobile phone app containing emergency first aid advice for parents.
"We have an absolute commitment to making use of digital communications and social media as a mainstay of our engagement with the public," says Thomas.
"It is testament to the way in which we are becoming known for using new and innovative ways of delivery to carry alerts and messages that have formed the core of the Red Cross’ work for 150 years."
The mind boggles at what might be invented 150 years from now that will make Twitter Alerts seem as outdated as town criers and church bells.