The civic centre in Prince Rupert was evacuated late Wednesday afternoon after a reported ammonia leak.
Prince Rupert RCMP said a container full of ammonia exploded, forcing everyone to clear out of the Jim Ciccone Civic Centre.
Everyone did get out, but some golfers on a nearby course who came to help were overcome by fumes. They were taken to hospital with non-life-threatening injuries.
No one else was injured.
Firefighters are waiting for the air to clear, and will then test the centre for ammonia before giving the go-ahead to reopen.