A man drowned in Lake Washington while trying to rescue a child who had fallen off a boat near Chism Beach Park Wednesday evening, according to a Bellevue fire official.

Crews responded to the 800 block of Shoreland Avenue around 7 p.m. to reports of a child who had fallen off a boat and a man jumping into the water to try and help, Bellevue Fire Department spokesperson Lt. Camry Olsen said.

The child made it back on to the boat, but the man slipped underwater, Olsen said. When the Mercer Island Police Department’s marine patrol unit responded, they determined the water was at least 110 feet deep and “due to the time that had elapsed and the depth, a rescue was not possible,” fire officials said on Twitter.

As of 9 p.m., marine rescue crews hadn’t found the man and switched to a recovery operation, Olsen said.

Olsen said the ages of the child was not immediately known nor if there was an adult on the boat with them.

Mercer Island police will continue to investigate what happened, with help from the Bellevue Police Department.

No further information about the drowned man was available Wednesday night.

Correction: A previous version of this story reported incorrect information from the Mercer Island Fire Department that two children fell off a sailboat and into the water when the man attempted to help. The Mercer Island Police Department has since clarified that only one child was involved and that the child was on a motorboat, not a sailboat. An update to this story with further details is available here.