NEW YORK (AP) _ Authorities were investigating a fire in a high-rise apartment building on Manhattan's Lower East Side that seriously injured three residents.

The three-alarm blaze erupted Thursday evening on the third floor of the 26-story building. The flames engulfed just one apartment, but the dense, black smoke seeped through the high-rise. It took firefighters about two hours to bring the blaze under control.

Two residents were hospitalized in critical condition, and a third was seriously hurt but expected to survive, the fire department said. Two firefighters were hospitalized as a precaution, though as many as 30 were treated for minor injuries.

Two of the badly injured victims may have tried to use an elevator to escape the building, only to have the lift open on the same floor as the fire, said FDNY Deputy Chief James Daley.

On the 18th floor, Naomi Pena huddled with her children in a back room with the windows open. Smoke spread through their apartment before they were evacuated down a dark staircase about a half hour later, Pena said.

"It was hard to breathe in there," said her 7-year-old daughter, Elisha. "I'm glad we got out."

Copyright 2008 The Associated Press.