Excerpts from Chicago.cbslocal.com:

A Chicago Fire Department diver drowned while on a rescue call on the Chicago River in 2018, caused by a lapse in air management and inability to maintain buoyancy in the water.

The report suggests that if Juan Bucio had an alarm to alert him that his main air tank was empty, he may have been able to switch to his reserve supply.

The 43-page report was completed in June, three years after Bucio disappeared under the waves of the river near 26th and Ashland while searching for a missing boater. Bucio was pronounced dead after he was pulled out several minutes later.

The report suggests more training and fundamental scuba skills for CFD divers. It concluded that a dive computer (which is not required) could have helped alert Bucio of low air rather than relying reading gauges in the dark murky river.

Bucio was found with an entire reserve air tank still full. The report found that when Bucio’s main tank was out of air, it appears he could not inflate his vest for positive buoyancy and control. His 24-pound lead weight belt was also still on, which was further hindering his buoyancy.

Fire Department dive teams responded to a call about a man who fell off a boat on the Chicago River near Canalport Riverwalk Park on Memorial Day of 2018. The body of that man, Alberto Lopez, was recovered from the River several days later.

A helicopter dropped Bucio and his partner into the river to search for the boater. The two had been in the water for some time when they began swimming to a Chicago Fire Department boat.

Bucio and his partner were face to face in the water next to the rocking boat when Bucio’s head went under the waves. His partner placed his hands on the side of the boat to keep his head above water.

From the NIOSH Report:

NIOSH Report Executive Summary of the LODD of Chicago FD Diver  Juan Bucio