Boston Fire Department spokesman Steve MacDonald said the boy was helping his father shovel the snow in the Dorchester neighborhood but got cold, so his father started the car and the boy got inside the vehicle. MacDonald said the car exhaust was covered by a snow bank, causing the fumes to collect in the car.
"I don't know how long the boy was in the car, at some point the father was still working and was unaware of the boy's condition," said Boston firefighter Octavius Rowe, who lives nearby and went to help. "So very, very unfortunate."
When the boy was overcome by the fumes, the father went into respiratory arrest and emergency workers took both to Boston Medical Center, officials said. The boy was pronounced dead at the hospital. No names were released.
Rowe said he was at home when he noticed a commotion in the street. He went outside and saw the father leaning against a pile of snow, Rowe said.
"I came over to the car where it all started and the father appeared to have lost consciousness," Rowe said. "He was semi-conscious and laying on the snow bank, and I wanted to first get him off that cold surface."
Rowe said he put the man on a flat surface to revive him. He said the boy apparently had been taken into an apartment building where a woman was administering CPR. Paramedics from the fire department and Emergency Medical Services arrived and provided oxygen to the father to stabilize him and tried to engage him in conversation to keep him alert.
"He was responsive so we were able to, at least, get him up, get him to the stairs. He did say, 'My son, my son,' so he knew his son was involved or was in distress," Rowe said. "We were talking to him. He was moaning, but the only discernible thing that he said was 'My son.'"
Rowe said his understanding was that a snow plow had come up the street and had pushed snow back onto the bank, which then impacted the car's exhaust pipe.