London - A blast on Monday night at a concert in the northern English city of Manchester left number of people dead and injured. More on the terrorist attack: 20 killed: More on Manchester explosion: A bomb detonated as the first people were leaving a concert Initial report on the 'explosion' Multiple U.S. officials briefed on the investigation told NBC News that preliminary reports indicate that a single explosion took place outside the arena on the southwest side, opposite the Manchester Victoria transit station, which is part of the greater arena complex.
