The second-story floor of a burning building collapsed Tuesday morning in Baton Rouge as firefighters worked inside.

The collapse caused no injuries but complicated efforts to fight the blaze shortly before 6 a.m., Baton Rouge Fire Department spokesman Curt Monte said in a news release.

The fire at the vacant commercial building at 1495 Eddie Robinson Sr. Drive was quickly brought under control “but it took firefighters a significant amount of time to extinguish completely due to the collapse,” Monte said.

No firefighters were injured during the collapse, Monte said. “They recognized the signs of it and got out before they were in any danger.”

No one was inside the building when the fire started, Monte said.

The cause of the fire has not been determined, Monte said, adding that the building is considered a loss.