The last news I heard was 22 dead and 50 injured. Suicide bombers in the UK is a massive escalation for us, frankly we're stunned. As far as I know this is the first attack of this kind on mainland Britain.
According to the news the bomber was waiting in the foyer, along with parents and friends of the attendees, waiting for people to leave the concert. Another five or ten minutes and the fatalities could have been much higher.
Sadly this is not the first time Manchester has been the target of terrorist bombs. Lets hope it is the last.