Carino Vanorden, 24, was at the wheel Wednesday night when a trailer hauling crushed cars broke free of the big rig that was pulling it, cut across a rural, two-lane road and slammed into the minivan, his mother Kate Vanorden of Fayetteville said.
"There was zero time to make a maneuver," she said.
Vanorden said her adopted son was engaged to Lena Beckwith, 21, who also was killed when the minivan was hit in rural Cortland County south of Syracuse. The couple, who lived in DeRuyter, had not yet set a marriage date.
The sheriff's office said Friday investigators determined the cause of the crash was mechanical failure. A part intended to securely lock the coupling between the tractor and trailer failed, but investigators hadn't yet determined why, the sheriff's office said.
Trailers are typically attached to tractors by a "fifth wheel," in which a pin on the trailer fits into the center of a large horseshoe-shaped piece of metal and is secured by an automatic locking device.
Also killed in the crash were 26-year-old Teresa Bush, her two daughters, Alexis, 4, and Jasmine, 5; and Alyssa Mead, 7; and Tyler Mead, 4.
"The kids would just love going out with him," Kate Vanorden recalled.
Shawn Mead, the father of the two Mead children, was taken to Upstate University Hospital in Syracuse. He was released from the hospital Friday.
The large majority of truck crashes are attributed to driver error. But even in cases of mechanical failures, runaway trailers are rare.
Looking at five years of fatal crashes involving large trucks, 0.10 percent - or one in a thousand - involved the truck's couplings, hitches or chains, according to an analysis of federal data from 2007-2011 by the Federal Motor Carrier Safety Administration.
"It's very rare but it does happen, and can be very serious. It's one of the things we inspect for," said Ralph Craft, a crash data analyst with the federal agency.
Ted Scott, the American Trucking Association's director of engineering who is not involved in the upstate crash investigation, said the automatic locking device setup has proved safe and requires a manual release.
"It is possible that with an old, not properly maintained fifth wheel that the device can get loose, the sides can wear away, the hole that the pin fits into is no longer snug and rigid," Scott said. "And at that point it can come loose, but that's a rarity."
The truck was owned and operated by Newton Salvage of Georgetown, N.Y. Messages left Thursday and Friday on an answering machine at Newton Salvage were not returned.
Kate Vanorden said her son had two part-time jobs and was saving money to go to Onondaga County Community College to study auto mechanics. She said she adopted him as a baby - her first of six adopted children - and said he loved cars and trucks since getting his first Matchbox car.
"He'd buy junkers, fix them up then he'd sell them on Craigslist, make a little money, buy a better car, fix that one up," she said.
She said her son had been living with Beckwith, her parents and her extended family. Teresa Bush was Beckwith's cousin, she said. She wasn't sure how the others were related.
AP writers Michael Hill and George M. Walsh contributed to this story from Albany, N.Y.