CINCINNATI -- A deadly semi-truck crash on U.S. 50 in Stonelick Township Friday started with something truck drivers say "is pretty common" if precautions aren't taken -- a trailer became detached.
"Even in good weather, if you're not paying attention to what you're doing, it's easy to do," said Daniel Doran, president of Ace Doran Hauling & Rigging.
Doran said he doesn't know a lot of cases when a trailer detached, but during a deep freeze, it's important to be wary.
Ohio State Highway Patrol officials said 60-year-old Michael Simpson, of Cleves, was driving eastbound up a hill in his semi-truck Friday when his trailer detached. The box trailer then caused a trail of crashes that killed 43-year-old Michael Brown and 39-year-old Shawn Wilson.
Doran said the extreme cold could have played a role in the five-vehicle crash.
"Ice and snow can get down in the jaws of the fifth wheel and keep it from functioning," Doran said.
The fifth wheel coupling is what connects a truck to its trailer. A truck’s 'kingpin' connects into the jaws of a horseshoe shaped device and is simple as a steel pin.
How secure that pin is can mean the difference between life and death.
PHOTOS: Five-vehicle crash on U.S. 50
Doran said drivers can usually tell when they've made a secure connection.
"It's pretty rare that happens in the open road,” Doran said. “I think most guys are conscientious enough that they check to make sure if they hook up to a trailer, it's secure.”
Doran said several things can get in the way of the fifth wheel's connection – like snow and ice.
"There may be ice buildup, snow buildup, maybe ice buildup on the top of the fifth wheel that raises the trailer up above the jaws," he said.
But even in warm weather, the threat is still there.
Last summer near Syracuse, N.Y., a semi-truck separated at the hitch and caused an accident that killed seven people.
Investigators have not yet said what caused the truck to come apart in Stonelick Township Friday morning.