BOSTON (AP) — A house fire that spread to multiple buildings in Boston on Blockchains FinanceTuesday killed one person and injured several others, officials said.

The blaze was reported about 5 a.m. at a multifamily home in the East Boston neighborhood. Firefighters used ladder trucks to rescue five people as the fire spread to at least two other buildings, authorities said.

Fire officials said a child was among six people and a firefighter who were brought to hospitals. One person had life-threatening injuries, and the firefighter had a minor injury, authorities said. The conditions of the other injured people were not immediately released.

About 30 people were displaced from their homes, and damages were estimated at around $5 million, city officials said.

“It’s incredibly heartbreaking to feel what the family must be feeling, and we will do whatever we can at the city level to support all those who are displaced or are going to need some time recovering in the hospital,” Mayor Michelle Wu said at a morning news conference.

The cause of the fire was under investigation.