A fire that raced through a two-family home in northern Connecticut on Tuesday night killed four children and several animals as firefighters struggled with rescue efforts because of clutter, authorities said.

The four children who died in the Somers blaze were ages 5, 6, 8 and 12 and lived in one side of the house with their mother and three other siblings, fire and town officials said. The mother was not home at the time and her 19-year-old daughter, who was watching over the other children, escaped by jumping out of a second-story window, First Selectman Tim Keeney said.

It wasn't immediately clear what caused the fire in the close-knit town of just under 10,000 people about 25 miles (40 kilometers) northeast of Hartford. State and local officials were investigating. The blaze did not appear to be caused by a criminal act, State Trooper First Class Pedro Muniz said.

A neighbor described a heartbreaking scene with people screaming and the three survivors jumping from the second floor.

Roache said firefighters rescued three dogs from the home, but a litter of puppies died.

The 19-year-old daughter and two of her siblings survived. One of them had serious burn injuries and two had minor injuries, said officials, who did not disclose which sibling suffered the serious injuries.

Four people who were in the other side of the house escaped without major injuries. A firefighter suffered a burn injury and was treated and released from a hospital, officials said.

Authorities said the victims' names were being withheld pending autopsies.

The fire was reported shortly before 10:30 p.m. and the first firefighters arrived about five minutes later to find the entire front of the house on fire, Roache said. The flames made it difficult to enter through the front, and items in the home made it difficult to get through the back door, he said. Around 60 firefighters from 12 agencies responded to the blaze, he said.

"It's a tremendous loss for the town," Keeney, the first selectman, told reporters at the scene Wednesday morning. "An incredible loss, a tragedy the town hasn't seen forever that I'm aware of. I've lived here my whole life."

The family that lost loved ones in the fire was offered help by the American Red Cross and social service officials, authorities said. A local aid fund was accepting donations for the family, officials said.

A GoFundMe has been set up.