HOOKSETT — New Hampshire State Police investigators believe a faulty bearing in a wheel hub assembly caused the wheel on a tractor-trailer to fall off Wednesday, crash into the unmarked cruiser operated by the head of state police and then ricochet into a car being driven by a Concord woman, killing her instantly.
Lt. John Begin of state police Troop G said there are two reasons why a tire falls off a truck or car: The lug nuts are sheared off because they were not tightened properly, or the wheel hub assembly failed.
"Based on what we saw at the scene — the lug nuts were still attached to the wheel — it was a hub assembly failure," said Begin.
Meanwhile, a close friend of the woman who died in the crash, Kelly Anderson-Baker, said her family is trying to sort through the sudden death of the 40-year-old mother of three.
"She was really a great person, always friendly, always nice," said Gilford resident Valerie Cummings, who grew up with Anderson-Baker in Hill.
Anderson-Baker was commuting to work at Lawrence General Hospital, where she was a project manager for patient care.
"She was really a positive person, very driven," Cummings said.
The crash happened just after 8 a.m. Wednesday on Interstate 93, not far from the rest areas and state liquor stores. Alan Condon, 51, of Oakfield, Maine, was driving the rig hauling a modular home south on I-93 when the wheel fell off the trailer, bounced or rolled over a jersey barrier and hit the right front driver's side of the unmarked cruiser being driven on the opposite side of the highway by state police Col. Robert Quinn.
The wheel ricocheted off the cruiser and slammed into the front of Anderson-Baker's southbound Mazda CX-9. She died instantly.
Quinn was uninjured and reported the accident.
Police said Condon and an escort car following behind him continued on. Condon stopped and paid the toll and continued a short distance before pulling over to the side of the road, witnesses told state police investigators. The escort car stopped as well, but both vehicles continued on their way to Maine.
Maine State Police located the truck later in the day at a rest stop off Interstate 95 in Newport, near Bangor, Maine.
Anderson-Baker was born in Korea and adopted by her parents, who raised her in Hill, along with another Korean child, Cummings said. She said her mother was the former superintendent of the Merrimack County jail, and her father was a civil engineer.
Anderson-Baker had two children from a first marriage, and they attend Concord High School, Cummings said. She became the stepmother to a 7-year-old when she married Hans Baker, Cummings said.
"It's just really, really hard for them," she said.
When a wheel hub assembly fails, the cause is usually the result of a worn or overheated bearing due to the lack of lubrication, Begin said. He said a wheel coming off a truck is not common, but state troopers have seen it happen about 10 to 12 times in the past two years.
He said New Hampshire state troopers were in Maine Thursday to make arrangements for the trailer, which had 10 tires and five axles, to be brought back to Concord. It will then be gone over thoroughly by Troop G officers who are certified to inspect commercial trucks.
He said Crawford Homes of Houlton, Maine, which owns the truck, was cooperating with investigators.
It will take between 30 and 90 days for the inspection and report to be completed. Once done, it will be turned over to the Merrimack County Attorney's Office. The county attorney will decide whether criminal charges will be brought.
State police ask anyone who may have witnessed the crash or who has information about it or the driver of the tractor-trailer to call them at 271-3636.
Mark Hayward contributed to this story.