Abstract: At 8:15 p.m. on May 28, 2018, an employee was working as a fire fighter and diver for a big city fire department. A man fell into the South Branch of the Chicago River. The fire fighter and a coworker, his diving partner, had been deployed from a helicopter into the river to conduct dive rescue operations. During the attempt, the fire fighter surfaced with his partner. Then he subsequently sank to the bottom of the river. At that time, he lost communication with the fire department. Divers from the department's marine unit searched for fire fighter. After several minutes, they located the fire fighter and pulled him out of the water with his diving equipment intact. Despite resuscitation attempts by paramedics on the scene and at the hospital, he was pronounced dead at 10:02 p.m. that same day.