LINCOLN, Maine — Two firefighters were injured battling a fire that destroyed a Lee Road apartment building early Friday. Tenants were able to get out safely, fire officials said.

Lowell fire Capt. John Herlihy pulled a muscle as he slipped while dragging a fire hose from a truck at the fire at 121 Lee Road, and Lincoln firefighter Terry Upcott suffered from heat exhaustion.

Both men were released from Penobscot Valley Hospital of Lincoln later that day.

Ice clogged fire hoses and froze in slushy patches as firefighters tried to put out the fire at the one-story apartment building. About 30 firefighters from Burlington, East Millinocket, Howland, Lee, Lincoln and Lowell battled the blaze, Lincoln Public Safety Department Director Dan Summers said.

“My feet were so cold I couldn’t even stand on them anymore,” Lincoln firefighter-engineer Cory Stratton said.

The cause of the fire is undetermined due to the extensive damage, said Sgt. Tim York of the state fire marshal’s office.

The incident forced the closure of Lee Road, which also is known as Route 6, from just west of Frost Street to Evergreen Drive. Traffic was rerouted over Frost Street and Highland Avenue.

The fire was first reported at about 3:15 a.m. when a passer-by called 911 after seeing smoke coming from the eaves of the building. Lincoln police Sgt. Glenn Graef, the first emergency responder to arrive, confirmed the report within three minutes and alerted building owner Eric Ring, who was in one of four apartments there, Summers said.

Firefighters who arrived about six minutes after the 911 call tried to douse the flames at the source, but the flames and speed at which they consumed the building drove back the interior attack, Lincoln Fire Department Lt. Bob Bean said.

Firefighters estimated that it took about 15 minutes for the flames to go from a rear apartment, where the blaze appeared to have ignited, into the eaves of the building.

Summers and Bean said they did not know how many people lived there. Two of the four apartments at the building, which was once a shoe assembly factory, were occupied, Bean said.

Kristina Troxell, who lives next door at 117 Lee Road, said that her first inkling of the fire was the emergency lights that flashed into her home after her husband’s alarm clock went off at about 5:15 a.m.

Ring had been renovating the building’s rear apartments and planned to fix a faulty septic system, said Amanda Woodard, Lincoln’s code enforcement officer.

“I saw him out here plowing just yesterday,” Troxell said.

Ring and Graef, who went off-duty after the fire, could not be reached for comment.

Firefighters left the fire scene at 12:30 p.m. and were called back for a rekindle to the rear of the building at 4:15 p.m. They left again at about 5:45 p.m. Some Lincoln firefighters worked 13½ hours on Friday as besides the fire, they responded to three ambulance calls and a reported propane leak on School Street, firefighters said.