The Philadelphia Inquirer ( http://bit.ly/Q44sHH) says about 160 fire and emergency personnel evacuated the 55-unit 1600 Church Road complex and battled Friday night's blaze.
Glenside Fire Chief Joe Stuckert said no major injuries were reported, calling that "a blessing."
He says the cause remains under investigation, but it was originally reported as a stove fire in a third-floor unit.
Officials said some residents had to be rescued from balconies. At least five residents and two firefighters had minor injuries.
Dave Schrader of the American Red Cross of Southeastern Pennsylvania says about 100 people were displaced, ranging from elderly residents to students from nearby Arcadia University.
Information from: The Philadelphia Inquirer, http://www.philly.com