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. / P6 ]/ E. p- k7 g- D) U: A1 n, C" G 2 ~" }0 V8 {5 G1 BThey say they are treating it as a "terrorist incident" as they investigate.