The Associated Press

Photo courtesy of the MacDonald family Mont. Firefighter Michael MacDonald.

HELENA, Mont. — A soon-to-be father who loved being a firefighter was among six people killed when two medical helicopters collided in Arizona.

Michael MacDonald, 26, was fighting wildfires at the Grand Canyon when he was bitten by an insect on Friday and taken to a nearby hospital, said Tyson Runningwolf, fire management officer for the Blackfeet Nation in Montana.

MacDonald suffered anaphylactic shock, a life-threatening allergic reaction, from the treatment he received for the bite, and was being transported to the Flagstaff Medical Center in Arizona when the helicopters collided Sunday afternoon.

One of the helicopters was operated by Air Methods from Englewood, Colo., and the other was from Classic Helicopters of Woods Cross, Utah. Both aircraft were Bell 407 models.

Investigators plan to begin examining the remains of the helicopters on Tuesday.

It was the ninth accident this year involving emergency medical aircraft, bringing the number of deaths to 16, National Transportation Safety Board officials said Monday.

MacDonald was aboard the chopper coming from the South Rim of the Grand Canyon, about 70 air miles from Flagstaff, farther by ground. The drive on well-paved roads takes about 90 minutes. The other chopper was coming from Winslow, about 50 miles away on Interstate 40.

Three people died on each of the two Bell 407 helicopters: the pilot, the patient and a flight nurse on one chopper, the pilot, the patient and a paramedic on the other. A flight nurse on one of the helicopters was hospitalized in critical condition.

At the crash site Monday, wreckage from one helicopter sits as a pile of twisted metal among bent pine trees. One long rotor blade sticks up in the air, while another is bent up at a 90-degree angle. Green wire hangs out of the wreckage, and medical bags are strewn about. The smell of fuel lingered Monday.

More than 300 feet away, what was a helicopter is now a pile of burned metal in a clearing atop a mesa.

A surveillance camera from one of the hospital's parking lots captured the crash, but it will require technical work to remove the time stamp that blocks footage of the collision.

MacDonald was a "super nice kid" who loved being a firefighter, said his uncle, John Lee Hall, of Browning, Mont. He grew up on the Blackfeet Indian Reservation, but had been living in Missoula and attending the University of Montana as a physical education major. He enjoyed playing basketball in his free time, Hall said.

"He was very happy-go-lucky and always had a smile on his face," Hall said. "He had friends all over. There was nobody that didn't like Mikey."

MacDonald and his girlfriend were expecting their first child next month. "The family is devastated," said Nora Kennedy, a family friend and distant relative.