Minneapolis' Webber Pool temporarily closes after man puts "unknown white substance" into water

MINNEAPOLIS — The Webber Natural Swimming Pool in Minneapolis is temporarily closed after a man put an unknown white substance into the pool water.

The Minneapolis Park and Recreation Board said park police were called to the pool around 4:30 p.m. on Thursday. A man had been "acting irrationally" and put his hand on the shoulder of a lifeguard, the board says. The man then also threatened to push the guard into the pool.

After he made several verbal threats to staff and pool visitors, a witness said they saw the man deposit an unknown white substance into the pool. He then left the pool on foot, according to the board.

Water quality staff are determining the best process for testing pool water, officials say. The staff is working with the Minneapolis Fire Department hazmat team, the regional chemical assessment team and the Minnesota Department of Health.

Friday afternoon, the suspect was identified. The Minneapolis Park Police Department is investigating the incident.

According to the park board , the Webber Pool uses a natural filtration system instead of chemicals to treat the water, mimicking "the natural cleaning mechanisms of a pond or lake."