MINNEAPOLIS  — Brandi Craig awoke before dawn Friday to a desperate scene as firefighters smashed their way into a duplex that was engulfed in flames across the street in her north Minneapolis neighborhood while tenants, including a family with seven young children, shouted for help.

“They were all screaming,” Craig said, her face twisting with emotion. “Once they stopped screaming, it was over.”

The fire killed five people, including at least three children, and injured several others, officials said. The cause of the blaze was being investigated, though fire officials say it appeared to have started on the second floor. The names of the dead were not immediately released.

Among those injured was Troy Lewis, according to neighbors and his landlord. Lewis was in satisfactory condition Friday night at Hennepin County Medical Center. Two of his daughters, Shaca and Electra Lewis, were in critical condition.

Craig said Lewis’ wife died in November after an illness and that he lived in the upper level with seven children, ages 1 to 9.

Craig said that just the night before she and her fiance had stopped by to give the kids some soft drinks.

“We gave them hugs and kisses and told them we’d see them in the morning,” she said.

Instead she woke up to see the house engulfed in flames, a blaze already too dangerous for her to do anything but watch as firefighters broke down the door and tried to rescue the kids. She saw them bring two apparently already dead children from the building. At that point, she said, she couldn’t watch anymore.

“It just took everything away from me,” she said.

Minneapolis Fire Chief John Fruetel said three children died at the scene. The Hennepin County Medical Examiner’s Office later confirmed the two additional deaths but did not release any information about the victims. Fire officials said 15 people lived in the duplex.

Fruetel said firefighters encountered heavy smoke and fire on the second and third floors of the duplex as they searched for victims and survivors. It took firefighters about 2 1/2 hours to put out the blaze.

He said investigators were still trying Friday to determine a cause, but it appeared the fire started on the second floor, in the center of the building. He said a space heater was found on that floor, but he didn’t know if it was in use before the fire began.

He said the building was up to code and smoke detectors were hard-wired and appeared to be working. He said he didn’t know if the smoke detectors went off before this fire.

Gov. Mark Dayton issued a statement offering condolences to the family and friends of the victims, and thanking firefighters and other first responders “whose heroism saved lives this morning.”

Minneapolis Public Schools confirmed two of the children killed were students at Bethune Community School, in the first and second grades.

City records show an inspection report last summer called for repairs to smoke detectors in the unit, among other violations. City spokesman Matt Laible said all of the violations were taken care of and that the unit’s rental license was renewed just a week ago.

The owner of the property, Paul Bertelson, said Lewis and his family moved in about six to eight months ago.

“There were no disturbances. They were good tenants,” he said, adding that the upper unit included two bedrooms on the second floor, and three on the third floor.

Bertelson’s company identifies distressed or foreclosed properties, refurbishes them and rents to low-income families. He said the 102-year-old duplex had smoke and carbon monoxide detectors. The upper unit is heated by permanent baseboard units.

One of the more than 40 firefighters who responded to the scene was injured. Fruetel said he suffered a muscle strain.

The Red Cross was assisting three adults and four children who were displaced by the fire.