ROCHESTER, N.Y. (AP) — A human body was found Tuesday in a western New York reservoir that supplies drinking water to parts of Rochester, prompting city officials to advise residents to boil their water before consuming.

Workers with the city’s Water Bureau discovered the body in the Highland Park Reservoir at around 8 a.m. while doing routine rounds, officials said. The reservoir was immediately disconnected from the public water supply, with plans to drain and clean it.

Police divers removed the body of an adult male from the water, authorities said. The circumstances of the death were not immediately clear. Police were investigating, and the medical examiner’s office was working to identify the person.

Testing indicated the water was safe, the city said in a notice to residents. The boil water advisory was issued to several neighborhoods as a precaution, officials said, and the reservoir will not be returned to service until after it is drained and cleaned.

“This is a very, very sad situation,” Mayor Malik Evans said at a news conference. “But it compounds that being that this happened near our water supply it’s important that we exercise this abundance of caution.”

Officials with the Rochester City School District ordered all schools to close Wednesday because of the boil-water advisory.

The city advised residents to bring tap water to a rolling boil, boil for one minute and cool before using. It said boiled or bottled water should be used for drinking, making ice, washing dishes, brushing teeth and preparing food until further notice.