The injured were taken to St. Mary's Medical Center, Aria Health-Bucks County Campus, and Lower Bucks Hospital. The firefighters were released Saturday.
Bucks County spokesman Chris Edwards called the blaze "one of the largest residential fires in recent history" in the county. Edwards said the fire was cooking-related.
The Red Cross consulted with about 50 people during the night, 10 of whom slept in a shelter at an elementary school.
The Red Cross says it expects other residents, who may have fled the fire and stayed with friends or family members, to eventually return to the scene and obtain help.
Red Cross volunteers continued to meet with the displaced through Saturday afternoon. The organization is assessing each resident's property loss, seeing if they are insured, and giving out debit cards for immediate needs. The complex required residents to carry rental insurance, Edwards said.
Residents and about 10 Red Cross volunteers from Bucks County gathered at the scene Saturday afternoon.
Edwards said the residents were lucky that fire broke out when people were still awake rather than early Saturday morning.
He also said a young child may have saved lives by knocking on doors and alerting residents to the danger.
Ella Hamell, 73, had her door knocked on but was reluctant to open the door because she had only lived in her building for a week.
But when she saw smoke and fire, she sprinted out the door, without her purse, phone, or shoes.
"Probably by the end of the day it'll hit me," Hamell said Saturday afternoon. "I know I got to keep going."
Kristine Vernola, 42, had been through three fires before Friday's. Visiting her daughter's apartment in the evening, the family initially thought the air conditioner was burning. When they opened the balcony doors, they realized smoke was everywhere.
Vernola said she had experience with losing her belongings.
"I explain it's from joking to crying to joking to crying - it's a roller coaster," she said. "These things are replaceable. The lives aren't."
Vernola said her family's hardship had "come full circle" because she stayed with her daughter after her home in Long Island was destroyed during Hurricane Sandy. Now that her daughter's home has been destroyed, the daughter will stay at the mother's.
"That's what family's about," she said. "You help each other no matter what."
Contact Theodore Schleifer at 215-854-5607, firstname.lastname@example.org, or follow @teddyschleifer on Twitter.