PLANE CRASH: Video shows smoke billowing and flames spewing after a World War II-era bomber plane crashed just outside Bradley International Airport north of Hartford, #Connecticut https://t.co/yAdOAGaT8o pic.twitter.com/StpDA1E34x — Eyewitness News (@ABC7NY) October 2, 2019

EMBED >More News Videos Any photo you can find of Lt. Col. William Bonelli during World War II is black and white, but his memories are in color, and each detail is as loud as the engines of his old B17.

WINDSOR LOCKS, Connecticut (WABC) -- A World War II-era plane crashed in a fireball as it tried to land at a Connecticut airport Wednesday morning, leaving at least seven people dead.The four-engine, propeller-driven plane struggled to get into the air and slammed into a maintenance shed at Bradley International Airport just before 10 a.m. as the pilots circled back for a landing, officials and witnesses said.A fire with thick black smoke could be seen rising from near the airport in Windsor Locks, and a fire-and-rescue operation commenced.There were 13 people on board, 10 passengers and three crew, and officials confirmed there were fatalities but would not say how many.Connecticut Public Safety Commissioner James Rovella said hours after the crash that some of those on board suffered severe burns and that it was too soon to say how many died."The victims are very difficult to identify," Rovella said. "We don't want to make a mistake."Still, a source with knowledge told ABC News that at least seven were killed. Additionally, one person on the ground in the maintenance facility was injured.Hartford Hospital confirmed it is treating six patients from the plane crash, three of whom are in critical condition. Two are moderately injured, and one is slightly injured.Two of the critically injured have burns and will be sent to the burn unit at St. Vincent's Medical Center in Bridgeport.Victims were taken to three hospitals, and family members can call a message center at 860-685-8190 for more information.Authorities confirmed two Simsbury firefighters were on board the crashed B-17 and that both survived, though the extent of any injuries is unclear. They were on the plane for personal reasons not connected to the fire department.The B-17 bomber crashed shortly after takeoff, and officials say the aircraft was five minutes into the flight when it reported it had a problem and was not gaining altitude.In recordings of audio transmissions, the pilot told an air traffic controller that he needed to return to the airport and land immediately. Asked why, he said: "Number four engine, we'd like to return and blow it out."The airport was immediately closed, but it was reopened by the early afternoon.The plane, civilian-registered and not flown by the military, was associated with the Collings Foundation, an educational group that brought its "Wings of Freedom" vintage aircraft display to Bradley International Airport this week."Our thoughts and prayers are with those who were on that flight, and we will be forever grateful to the heroic efforts of the first responders at Bradley Airport," the foundation said in a statement. "The Collings Foundation flight team is fully cooperating with officials to determine the cause of the crash of the B-17 Flying Fortress and will comment further when details become known."The New England Air Museum is near the airport.This same B-17 overran a runway after attempting to land in Beaver Falls, Pennsylvania, in 1987. There 12 people onboard that flight, three of which were injured.The NTSB has launched an investigation with a look into the history of the plane."That is a question we have asked, specifically for how many times it was flown prior to today along with the number of hours it has flown," said the NTSB's Jennifer Homendy. WPVI-TV in Philadelphia also profiled the exact same plane when a 98-year-old WWII veteran boarded the aircraft for his first flight in 75 years.Antonio Arreguin said he had parked at a construction site near the airport for breakfast when he heard an explosion. He said he did not see the plane but could feel the heat from the fire, which was about 250 yards away."In front of me, I see this big ball of orange fire, and I knew something happened," he said. "The ball of fire was very big."A smaller explosion followed about a minute after the first blast, he said. He saw emergency crews scrambling within seconds.(The Associated Press contributed to this report)----------