MANCHESTER, England (AP) " Police say they are treating an explosion at an Ariana Grande concert in northern England as terrorism. Greater Manchester Police says the blast killed at least 19 people, and the ambulance service says 59 people have been taken to hospitals.
Greater Manchester Police Chief Constable Ian Hopkins says police are treating the blast as an act of terrorism "until we know otherwise."
There was panic after the explosion, which struck around 10:30 p.m. (2130 GMT) Monday night as Grande was ending the concert.
Grande, who was not injured, tweeted hours later: "Broken. From the bottom of my heart, I am so so sorry. I don't have words."