A flag outside the Blue Hills Fire Station in Hartford, Connecticut is flying at half-staff to honor a firefighter who was killed and three others who were hurt while battling a massive blaze on Tuesday night in the city's North End.

Family members have identified the firefighter killed as Kevin Bell, 48.

He was pronounced dead at Saint Francis Hospital. Hartford police were still on scene on Wednesday morning and the road remains blocked off in the area.

According to state records, the last time a Hartford firefighter died while extinguishing a fire was in 1974.

Authorities did not publicly identify Bell on Tuesday night, but said he was a 48-year-old Hartford native and six-year veteran of the fire department.

"Our hearts are extremely heavy at this time with the knowledge that these brave men and women risk their lives every day to protect our city," Hartford Mayor Pedro Segarra said at the media briefing. "The simple acceptance of that responsibility on its own terms makes them heroes."

A second injured firefighter was transferred to Bridgeport Hospital with burns to over 10 percent of his body, according to Segarra. Although his injuries are serious, he's expected to survive.

Two other firefighters remain in stable condition at Saint Francis Hospital, authorities said.

According to Hartford Fire Chief Carlos Huertas, the two-alarm fire broke out at 598 Blue Hills Avenue around 6:30 p.m. An ambulance arrived shortly thereafter, and one firefighter was strapped to a stretcher, still conscious.

Thick black smoke poured from the two-story home, and neighbors recorded cellphone video of flames shooting through the windows.

A woman whose daughter lives in the burned house said she watched one of the firefighters jump out. The pastor of the homeowners' church group arrived to pray for the families involved and said everyone made it out safely.

Segarra spent the evening at Saint Francis Hospital comforting the family of the firefighter who lost his life.

"I have been with the family of the deceased firefighter for the last several hours and I can tell you that the suffering and the grief is indescribable," Segarra said at the press conference. "I want you to know that this gentleman is a true hero and he will never be forgotten."

Blue Hills Avenue was blocked off for several hours near the intersection of Litchfield Street. Authorities have not elaborated on the details or speculated about the cause.

"Our entire department is grieving but there will be no loss of service. What is important to understand is that one firefighter lost his life saving others," Huertas said, fighting tears.

The flames forced out two families, who are receiving housing help from the Red Cross, according to Huertas. Grief counseling will be available to those affected.

"Tonight's tragic events are another reminder of the incredible sacrifice that our state's first responders make on a daily basis," Gov. Dannel Malloy and Lt. Gov. Nancy Wyman said in a joint statement Tuesday night. "Our thoughts and prayers are with the family of the hero we lost tonight and those who were injured in the line of duty in our capital city."

Officials said the fire is under state and federal investigation.