Police say that 19 people have been killed and another 50 injured after an explosion at the Manchester Arena in northern England, where U.S. pop star Ariana Grande was giving a concert. ) a" d" L5 L: `. z( r 8 ~+ r' m8 B4 @2 W( [8 G: uThey say they are treating it as a "terrorist incident" as they investigate.