None of the injuries is serious, ABC7 has learned.
The firefighters were searching a third floor apartment for people trapped inside when they the ceiling gave way and fell on top of them, trapping them.
The roof remained intact. Other firefighters prepared to rescue residents trapped in the fire had to rescue their own who were trapped under the heavy rumble of the inch-thick plaster and wire ceiling three floors up.
"You can't see what's going on and you don't know what's happening until it's already done with," said Battalion Chief Robert Groszewski, Gary Fire Department.
The injured firefighters were rushed to Methodist Hospital in Gary with minor injuries. They were expected to be treated and released sometime overnight.
"We were able to get crews up there, we got them out from underneath the ceiling and we had to bring down the aerial ladder," said Groszewski.
Firefighters believe the fire was started in the third floor unit but have not yet determined the cause.