A man critically injured in a three-alarm fire Sunday at an Arlington County apartment complex is expected to survive, and nearly all of the more than 100 families initially forced to leave their apartments have returned or will be able to return by early Monday evening, authorities said.

Most families in the Harvey Hall Apartments — a complex on South Greenbrier Street that counts many senior citizens among its residents — were allowed back into their homes Sunday night, though those on the second floor, where the fire started, and a few others were displaced into Monday, authorities said.

Catherine Bucknam, director of community relations for AHC Inc., which owns Harvey Hall, said officials were encouraged by news that the man firefighters found unconscious in a smoke-filled hallway during the blaze was expected to survive.

“We’ve spoken to him," Bucknam said. “He is just fine.”

Fire investigators are still working to determine what caused the blaze at 850 S. Greenbrier St. that sent at least three people jumping from the second floor and forced firefighters to take another 20 trapped occupants down on ladders. But initially, it seems, catastrophe was averted.

Bucknam said the man fire officials found unconscious in a hallway appeared to have “fainted,” and he told apartment officials he expected to be released from the hospital Monday or Tuesday. Only three others had to be taken to the hospital, and all of those hospitalizations stemmed from preexisting issues, said Lt. Sarah-Maria Marchegiani, an Arlington County Fire Department spokeswoman.

County and apartment officials put up 16 residents in a hotel overnight after the fire, and others found their own accommodations as crews worked to repair the damage from smoke, fire and water, authorities said. Red Cross and county officials offered shelter to the families still displaced Monday at the Arlington Mills Community Center, though all except three families were expected to be allowed to return to their apartments by 5 p.m., Bucknam said.

Those three families — who lived either in the apartment where the fire started or in the units directly above it — were being relocated to other AHC properties Sunday, Bucknam said.

Marchegiani said while investigators did not yet know what caused the fire, they did not believe it was “suspicious” in nature. Fire officials estimated the blaze caused $50,000 in damage.

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