Facebook puts security check on

People who were in the vicinity of the suspected attack in Manchester are able to reassure their friends on Facebook.

If a disaster occurs, Facebook may decide to send a special message to anyone who may be in the disaster area. Users can then click on the 'I'm safe' button. An alert will automatically be sent to all friends of those users. The Facebook Safety Check was previously used in attacks in Berlin, Paris, Munich, Nice and Turkey.