Explosion, Fatalities Reported At U.K.'s Manchester Arena During Concert

Authorities warned people to avoid Manchester Arena in the U.K. late Monday following reports of an explosion during a concert. Manchester police said they are responding to a "serious incident" that occurred at the time of a concert by pop singer Ariana Grande. "There are a number of confirmed fatalities and others injured," Greater Manchester Police said in a statement on Twitter. Concertgoers reported hearing a loud explosion and several videos posted online showed concertgoers emptying the complex and several ambulances heading to the arena.