KANSAS CITY, Mo. — Two firefighters who saved two residents from a burning apartment complex in Kansas City were killed when a wall collapsed onto them after they had evacuated the building, authorities said.

Fire Chief Paul Berardi said two other firefighters were injured Monday night as the massive fire engulfed the building on the city’s northeast side. Berardi lauded the bravery of the two firefighters who died.

“They did not die in vain,” he told KSHB-TV. “They saved two civilians, carried them out of the second floor on ladders, before the wall collapsed.”

A clearly emotional Berardi identified the firefighters as 17-year department veteran Larry J. Leggio and 13-year veteran John V. Mesh at a news conference early Tuesday.

He didn’t provide their ages.

One of the two injured men was treated and released from the hospital overnight and the other could be released Tuesday, Berardi said.

Firefighters are still battling hotspots, but the fire is under control, Berardi said.

Fire Department Battalion Chief James Garrett told the Kansas City Star that the building was already heavily damaged when firefighters arrived. They were clearing an area where a roof had started to cave in about 7:30 p.m. when the building collapsed, Garrett said.

All firefighters were accounted for and outside the building when part of the second story caved in, forcing a wall to collapse outwards about 30 feet and trapping the firefighters who died, Berardi said.

“Our hearts absolutely go out to the families, both to their peers who are grieving but also to their family members who are at the hospital with them now,” he said at an earlier news conference.

The cause of the fire was not immediately clear. An investigation was ongoing.

On resident who escaped the flames told The Kansas City Star that he was at home when he heard shouts to evacuate.

“I was laying down and heard somebody yell, ‘Everybody get out,’” Lee said. “I opened my door and there was smoke really bad.”