Fifteen people were injured wen a ceiling collapsed during a Steve Aoki concert in Oslo.

Nearly 1,800 people were reportedly in attendance at the concert, which took place at Sentrum Scene. According to the BBC, the injured are currently receiving medical attention and are not believed to be seriously hurt.

In a series of tweets, Aoki said he was “saddened and shocked” by the collapse and hopes for a “speedy recovery” for those injured.