CHICAGO (CBS) — Funeral services have been set for Chicago firefighter Juan Bucio, who died while trying to rescue a missing boater in the Chicago River on Monday.

Bucio, 46, and his partner were searching the river Monday night after 28-year-old Alberto Lopez fell into the water when his boat hit rough water.

While swimming near a Fire Department boat, Bucio’s head went under the surface and he didn’t reappear. Crews located Bucio several minutes later, and pulled him out of the river, but he later was pronounced dead at Stroger Hospital. Lopez still had not been found, as of Wednesday afternoon.

Visitation for Bucio has been scheduled for Sunday, from 3 p.m. to 9 p.m. at the chapel at St. Rita High School, according to the Fire Department.

Bucio’s funeral will be at noon Monday at St. Rita, followed by burial at Mt. Auburn Cemetery in west suburban Stickney.

Chicago Fire Department diver Juan Bucio. (Photo supplied to CBS)

A 15-year veteran of the Fire Department, Bucio had been a diver since 2007. He leaves behind two sons, ages 9 and 10. He also has nine siblings, including a brother who works for the Fire Department and a sister who works for the Police Department.

Many of Bucio’s colleagues described him as one of the best.

“I trusted him with my life as a partner,” said fellow Fire Department diver Brian Coffman. “He was great in the water. He was one of the best we had.”

Coffman said he is numb and grieving Bucio’s death. Many others who knew him and worked alongside him are doing the same.

“Nobody expects to go to work and not come home, not even Juan. When Juan jumped out of the helicopter on that dive mission, Juan didn’t expect what happened to him,” said Fire Department Lt. Chris Meziere.

Chicago Fire Department diver Juan Bucio died after disappearing in the Chicago River while trying to find a missing boater on May 28, 2018. (Credit: Linkedin)

Bucio’s older son turned 10 years old on Tuesday.

“I feel for them,” said Firefighter John Metzger. “They should know that their father always talked about them and that’s what hurts the most.”

Bucio was a Chicago Police Officer before joining the fire department. He lived on the city’s Southwest Side.

“You want to know what a hero is,” said Deputy District Chief Ron Dorneker, “it’s Juan Bucio.”

It’s still not clear how Bucio died. An autopsy was performed, but the cause is pending further studies and investigation.

The Chicago Fire Department is also still investigating the circumstances of his death.