LEWISTON, Maine — Three multistory apartment buildings in the downtown area were destroyed in a fire late Monday afternoon that left 75 people homeless but caused no apparent injuries, officials said.

The fire started in a condemned three-story building at 105 Blake St. just before 4:30 p.m. and spread to two neighboring three-story buildings at 172 Bates St. and 82 Pine St. Thick smoke filled the city block, engulfing buildings, including Saints Peter and Paul Basilica on Ash Street. Every building in the block was evacuated and hundreds of people lined nearby streets to watch the firefighting activity.

Jessica Ramsey-Nguyen said she was with her 5-day-old baby in their third-floor apartment at 105 Blake St. when she heard a loud bang, smelled smoke and went to the kitchen to see flames and smoke coming in the window.

“I grabbed my baby and left,” she said. Her dog perished in the blaze, she said.

Within minutes the fire jumped to the back of 172 Bates St., and on to nearby lawns. According to firefighters, the roof at 82 Pine St. caught fire just after 5 p.m. and smoke rolled out of the third floor minutes later, with the fire quickly spreading through the building.

By 7 p.m., the roof and some interior floors had collapsed.

The demand for water was so high that firefighters talked about the strain on the hydrant system, worried that there wasn’t enough pressure to quickly knock down the fire.

Police evacuated all of the buildings around 105 Blake St., police Chief Michael Bussiere said.

Firefighters later did limited searches of the buildings, and at about 5:30 p.m., Lewiston Fire Investigator Paul Ouellette said a resident in one of the buildings was not accounted for, but that person might have been in the crowd.

Several neighbors saw the smoke, grabbed their pets and got out of surrounding buildings.

Michael Marquis, who had just moved into a nearby third-floor apartment on Blake Street, said he heard crackling and a “pow” and looked outside to see the fire.

He said he saw his neighbors had all been able to get out with their pets.

Kevin Barrett, who had been walking to the post office, said he saw a little fire in one of the apartment buildings and saw people rushing toward it and thought it was under control. By the time he came out of the post office, he said, the building was on fire.

“It went up like that,” he said.

Roberta Greenlaw lives on the second floor at Healey Terrace senior housing at 81 Ash St.

“I thought it was our building at first when I looked out and saw the smoke,” she said as she watched the activity while holding her little mixed-breed dog named Dude.

“I grabbed him, grabbed my purse and got out,” she said. She also moved her car because it was too close to the burning buildings.

The apartment building at 105 Blake St. was valued at $191,340, according to tax records, and is owned by Watkins Property Management. It had been condemned and was scheduled to be auctioned May 22, according to a neighbor.

The building at 172 Bates St. is owned by Caron Property Management and is assessed at $210,000. It had an “auction” sign hanging on the Bates Street side.

It was not immediately known who owned the Pine Street building.

City firefighters were working late into the night to douse flames and hot spots, assisted by departments including Auburn, Lisbon, Oxford, Topsham, New Gloucester, Turner and Mechanic Falls.

An investigator from the state Fire Marshal’s Office was at the scene Monday night.

Members of the American Red Cross and Salvation Army were at the scene to assist the homeless and provide food for those in need.