An ammonia leak at St. John’s-Ravenscourt School forced evacuation of the school and the cancellation of a charity walk.

Kendra’s Walk was scheduled to go ahead at 2 p.m. on Friday at the school. The event raises money for teens living with cancer.

A new date has been set and will be sent out.

“All students and staff were safely evacuated from the school buildings this afternoon and once the Winnipeg Fire Paramedic Service cleared the buildings everyone was able to safely re-enter the school,” a spokesperson for St. John’s Ravenscourt said in a news release.

Officials said the ammonia leak started in a vent near the roof.

Hazardous materials crews were able to contain the leak, and students were let back into safe parts of the school. They said it now just needs to be aired out.

Officials say if you inhale ammonia, it can be very dangerous.

Crews told CTV News no one was injured in the incident.