22 people are dead following a massive fire at a residential building in Jiangsu province over the weekend. Local authorities have arrested one suspect for allegedly setting the building ablaze and locking the doors.

China’s official Xinhua agency reports that the fire broke out at around 4:32 a.m. on Sunday morning in the city of Changshu, located less than 100 kilometers from Shanghai. The two-story building was being used by a dormitory for 29 people working at a local restaurant. Most of those living at the house were young migrant workers.

Investigators discovered traces of gasoline at the scene of the fire and found that all the doors of the building had been locked.

The suspect has only been identified as a man surnamed Jiang. Further investigations are underway.

[Images via NetEase]