Federal investigators have found fault with the Chicago Fire Department over a blaze that killed two firefighters last winter.

The firefighters were killed a few days before Christmas, after the roof of a burning vacant building on the South Side collapsed. The collapse injured 19 other firefighters.

In a July report, first covered Friday by the Chicago Tribune, federal investigators with the National Institute for Occupational Safety and Health say commanders outside the building didn’t have enough communication with the men inside who were fighting the fire. The report also criticizes the CFD for not giving every firefighter a personal radio, and for not having a system whereby firefighters could easily identify structurally unsafe buildings before entering them.

Spokesman Larry Langford said the fire department has since improved the flow of information at fire scenes, so that firefighters now give their commanders outside a more complete picture so they can change tactics, if necessary.

But giving each individual firefighter a radio probably wouldn’t have made a during the Dec. 22 blaze, he said.

“This is not the case of a fireman being lost in a large warehouse or a multiple story building,” Langford said. “We knew immediately there was a collapse, we knew immediately who was in the collapse, and we knew where to start looking” for the trapped firemen.

Nonetheless, Langford says all firefighters should have their own radios by next year, when the department switches over to digital communications.