An early morning fire swept through a two-family house in a working class neighborhood in northern Connecticut on Wednesday, leaving four people unaccounted for, fire officials said.

Firefighters had to wait for a warrant to enter the two-story home along the Connecticut River in Enfield. Fire officials planned to stabilize the building before going inside, searching for victims and investigating the cause of the blaze, fire department spokesman Mark Zarcaro said.

Authorities didn't release the names of the people who were missing.

Four of the six people who lived in the north side of the home were unaccounted for and ranged in age from about 40 to their late 60s, Zarcaro said. Residents of the home included an older woman and relatives including her adult daughter and two adult grandsons, family friend Jessica Rozalski of Enfield said.

"It's sad. It really is," Rozalski said as she stood on the street outside the home with a friend. "I've known them my whole life and now it's possible they won't be here no more. I don't know what to think."

Rozalski said she spoke with one of the residents of the north side of the home who tried to break windows to rescue people inside but was turned back by the fire.

The north side of the home was completely charred on the inside; the outside had burn marks around where the windows were and the roof sagged.

Firefighters said they couldn't enter the home when they arrived at about 6:15 a.m. because flames were shooting out of the building and the second floor had collapsed into the first floor. They said they tried to get in through doors and with a fire truck ladder to the second floor, but they also were turned away by the flames and heat.

Authorities said the building, about 20 miles north of Hartford, will have to be torn down.

A woman and her two sons, who are about 19 and 12 years old, lived on the south side and escaped to safety, said the woman's sister, Lisa Lape.

Lape said she saw a story about the fire on TV and Facebook and rushed to the scene from her home in Bristol. She ran up to firefighters and told them her sister, Mary Lapane, lived there.

Lape said her sister was in the shower when she smelled smoke and was able to escape with her family.

"She's in shock," Lape said of her sister. "She's OK. We're going to get through this."