Peoria Police are now hunting for an arson suspect after what appears to be a case of attempted murder.
Firefighters say the fire broke out around 5:00 Thursday morning, with flames engulfing the only door.
The four adults and two children inside were trapped on the second floor.
With their only exit blocked by fire and the apartment filling with smoke, they broke out back windows and jumped.
Two residents, Bianca Robinson and Erica Alexander, suffered broken legs and other injuries in the fall.
"They threw one mattress out," said Mike Ogburn, Peoria Fire Dept. Battalion Chief. "One person jumped onto that, and some more adults jumped out. One adult stayed in and dropped the children out to the bystanders and other adults down there."
Robinson is listed in fair condition at OSF Saint Francis Medical Center.
Hospital officials say Alexander has spent the day in the Emergency Room.
Damage to the apartment is listed at $2,500.
Peoria police and fire investigators are working together on the case.