Seven people were killed in a three-alarm fire at an apartment building in Lowell, Mass., a state Department of Fire Services spokeswoman confirmed Thursday.

In an e-mail to The Post, spokeswoman Jennifer Mieth said some people jumped from the three-story building, which was heavily damaged in the early morning blaze. She said eight of the nine units in the building were occupied at the time of the fire, which was reported about 4 a.m.

The death toll included three children, the Boston Globe reported. Family members told the Globe that 12-year-old Anthony Sak, 9-year-old Ryan Sak and 7-year-old Sayori Sak were killed in the fire, as well as their parents, Torn Sak and Ellen Vuong.

“He’s a family man. He loved his kids,” Sak’s brother, Thearan, told the paper. “My family, they live in a bad neighborhood, but they are not bad people.”

Deputy Fire Chief Patrick McCabe told the Globe that about 50 people lived in the building. Officials were still searching for victims in the immediate aftermath of the fire, but all missing persons had been accounted for by mid-morning, Mieth wrote.

Lowell Mayor Rodney M. Elliott told the Globe that officials would examine the building’s inspection records, saying authorities were “on top of this.”

“Today is a tragic day in the city of Lowell with this horrific fire,” Elliott told the paper. “The entire city mourns the loss.”

Lowell is about 30 miles northwest of Boston.

A police officer secures the scene of a burned three-story apartment and business building in Lowell, Mass., on July 10. (Elise Amendola/AP)

“I woke up to a child screaming, ‘Help me! Help me! Help me!’ one witness told WCVB. “I looked out the window, and I saw a child being held by their parents. They let go of the child, and the child dropped out of the window.”

Officials have not determined the cause of the fire, according to reports.

“There are a lot of possibilities here,” Fire Marshal Stephen Coan told the Boston Herald. “We can’t rush to judgment. We’re still processing the scene. It’s important we take apart each one of those units.”

Boston’s local Fox affiliate had footage from the scene:Boston News, Weather, Sports | FOX 25 | MyFoxBoston

This post has been updated to include additional details. Last update: 6:01 p.m.