About 100 people were evacuated from an apartment complex and children were kept after school when ammonia gas in ice-rink pipes warmed and caused a release valve to stick, filling Murray City Park and adjoining neighborhoods with fumes Friday afternoon.

According to Murray City Fire Lt. Paul Hansen, fumes were detected about 3:11 p.m. coming from pipes used to cool the ice in the winter. The park is located near 5200 S. State."The relief valve was stuck in an open position. It was possibly frozen or rusted," Hansen said.

Officials evacuated residents from the Park Terrace Apartments, 340 E. Vine St., and kept students at Parkside Elementary, 5175 S. 495 East, inside until parents picked them up. Those living in homes bordering the park were advised to stay inside and police blocked foot traffic into the park, said Murray Police Capt. Ken Killian.

Firefighters allowed apartment residents to return at 4:45 p.m.

Murray Fire Capt. Bob Fonger said the mile-long rink pipe system had been recently drained into a tank, but residual gas had expanded when the sun warmed it.