A chlorine leak at Weyburn's Leisure Centre caused the evacuation of the building Friday afternoon.

Johnny Knox was at the pool with his grandson when he noticed an overwhelming smell of chlorine.

He went outside the seating area to grab fresh air. After returning, the smell continued to bother him so he asked his grandson to get out of the water.

"And then all of a sudden the lifeguard blew the whistle to clear everybody out and almost everybody was coughing like crazy," he said.

The evacuation was around 3 p.m., when an alarm was triggered due to the chlorine leak.

As for the cause, City of Weyburn staff say maintenance was being on the chlorine system earlier in the day, which required the chlorine tanks to be shut off.

When the maintenance staff turned the tanks back on-line, a value failed and started to leak the chemical.

The tank was shut off once the alarm was triggered and maintenance crews worked to isolate the chlorine system. During this time, the Leisure Centre staff evacuated the patrons.

Knox said his grandson threw-up once outside the Leisure Centre and again at home.

City staff say no emergency crews were required for the incident and there are currently no reports to the city of injuries.

Wind may have been a factor in why the smell of chlorine entered the pool area through the air ducts. City staff also say if the alarm detects even a minimal amount of chlorine, warnings will be set off.

The Leisure Centre reopened at 4 p.m. on Friday.