At 8:18 p.m. firefighters were called to the two-story brick house where the fire started on the first floor of the building, which is currently being rehabbed, Fire Commissioner Jose Santiago said.
"Lots of building supplies lying around," Santiago said.
When five firefighters started to climb a staircase in the house, it gave way and they all fell. Four firefighters were injured and transported to Resurrection Medical Center in good condition.
"Just bumps and bruises," Santiago said.
The fifth person who fell was not hurt.
The building was unoccupied at the time of the fire and the cause is still under investigation.
The extent of damage to building was also unknown, but fire officials did say the fire was well-contained by firefighters who continued to fight the blaze after the injured firefighters were taken to the hospital.
A Mayday alarm was called, along with a 2-11 alarm and an Emergency Medical Services Plan 1, sending five ambulances to the scene.