Picture of a B-17 flying at an airshow (Picture: US Department of Defense).
Seven people have died after a Second World War-era B-17 bomber crashed on Wednesday.
The aircraft encountered mechanical trouble on take-off.
The four-engine, propeller-driven plane struggled to get into the air and crashed into a maintenance shed at Bradley International Airport as the pilots circled back for a landing, officials and witnesses said.
It was carrying 10 passengers and three crew members.
Connecticut Public Safety Commissioner James Rovella said hours after the crash that some of those on board were burned and "the victims are very difficult to identify."
Some of the survivors of the crash were critically injured, authorities said.
One person on the ground was also hurt in the crash and a firefighter involved in the response suffered a minor injury.
The death toll of seven could rise, Mr Rovella said.
He said some lives were likely saved by the efforts of people including a person who raced to help the victims and people on the plane who helped others to escape the fire by opening a hatch.
"You are going to hear about some heroic efforts from some of the individuals that were in and around that plane," he said.
The retired, civilian-registered plane was associated with the Collings Foundation, an educational group that brought its Wings of Freedom vintage aircraft display to the airport this week.
"Right now my heart really goes out to the families who are waiting," Governor Ned Lamont said.
"We are going to give them the best information we can as soon as we can in an honest way."
The plane was a few minutes into the flight when pilots reported a problem and said it was not gaining altitude, officials said. It lost control upon touching down and struck the shed.
Only a few of the roaring Boeing B-17 Flying Fortresses are still airworthy.
The Collings Foundation said that the same plane in Wednesday's accident also crashed in 1987 at an air show near Pittsburgh, injuring several people.
Hit by a severe crosswind as it touched down, the bomber overshot a runway and plunged down a hillside. It was later repaired.
The B-17 was built in 1945, too late for combat in World War Two, according to the foundation.
It served in a rescue squadron and a military air transport service before being subjected to the effects of three nuclear explosions during testing, the foundation said.
It was later sold as scrap and eventually was restored. The foundation bought it in 1986.