Music world is stunned

FANS AND CELEBS reacted with horror Monday night to the news that a deadly explosion ripped through the crowd outside an Ariana Grande concert in England.

The 23-year-old performer was “OK” but devastated, her reps told Billboard.com. Worried colleagues still tweeted their concern for the “Break Free” singer, who had just wrapped up a show at Manchester Arena when the blast sent everyone running at about 10:30 p.m.

“Tearing up imagining innocent concert goers losing their lives . . . praying for everyone and all #arianators,” tweeted Demi Lovato, amid reports at least 19 people were killed and another 50 injured.

“Praying for everyone at @ArianaGrande’s show,” wrote Katy Perry.

The 1980s British performer Boy George said he was “so desperately sad about Manchester.”

Celebrities outside the music world also showed support.

“Heart breaks for everyone at the @ArianaGrande show — terrorism and hatred disrupting a magical escapist experience. Sending all love,” wrote “Girls” star Lena Dunham.

Fan Morgan Kennelly was among the thousands who shared support to the victims and distress over the incident. “I can’t believe what’s happened at @ArianaGrande concert. My heart is full of sadness for everyone involved. Prayers,” tweeted Kennelly. “Very Sad!”