A family friend survived by jumping from a second-floor window as fire swept through a duplex early Saturday, killing a woman and four children and leaving her husband in critical condition.

A neighbor spotted the flames just before 6 a.m., but police who arrived first couldn't reach the second floor because of the heat and flames, Police Chief Trevor Whipple said.

Firefighters made their way in and were able to pull the bodies from the blaze.

Kimberly Stoltz Foster, 30, and her children, Tory Stoltz, 12, and Brett Stoltz, 9, died in the fire, along with her stepchildren, Christa Foster, 8, and Mikayla Foster, 6. Her husband, Arthur Foster, 25, was hospitalized in critical condition.

An adult visiting the family, Jeremy Smith, 26, jumped from a second-floor window and was being treated for non-life-threatening injuries, authorities said.

Vermont State Police were investigating the cause of the fire, but Whipple said early findings showed no sign that it was suspicious.

As the last victim, Kimberly Stoltz Foster, was carried from the building, firefighters removed their hats and formed a line. Neighbors watched from a snowy sidewalk across the street, one of them crying in the arms of another.

The deadly fire hit hard in Barre, a closeknit town of about 9,000 residents 10 miles southeast of the state capital, Montpelier. Arthur Foster, who was in critical condition, is the fire chief's nephew, officials said. Earlier this year, the town lost three other children who drowned in a stream.

"It's just almost too much to bear for our sweet city," said Mayor Peter Anthony.

Schools were preparing to help the children's classmates deal with the tragedy. All four children killed in the fire Saturday attended schools in Barre.