Kansas City, Mo. ? A second of five firefighters injured in a blaze at a 1920s building on Friday was released Saturday from an area hospital, officials said.

The firefighters were searching for the source of the fire when there was a flashover, which occurs when the contents of a room heat to their ignition point and simultaneously burst into flame.

All five injured firefighters were able to make it out on their own and were rushed to Kansas University Hospital in Kansas City, Kan. A sixth firefighter was taken to a hospital but not treated.

Battalion Chief Joe Vitale said firefighter Jeremiah McDowell was released about noon Saturday. Firefighter Alfredo Katamura was treated and released Friday.

He said three men remain hospitalized: firefighter Eric Rose, in serious condition; Capt. Ron Gibbs, in fair condition; and Capt. Bruce Stiles, in good condition. Vitale said the men’s injuries were not life-threatening.

“They are doing well,” he said.

He said a damage estimate was not immediately known and it could be Monday or Tuesday before the cause of the fire is known.

The burned building included a playhouse that once housed burlesque, vaudeville and silent film. The playhouse became a movie house known as the Waldo Theater and later housed theater productions as the Waldo Astoria.