The crash happened just after 2:30 p.m., forcing Ontario Provincial Police to close the highway's westbound lanes from Joyceville Road to Highway 15.
In a statement to CBC News, Kingston General Hospital said between 15 and 20 people had arrived at the hospital, "most of whom have non-life-threatening injuries."
Frontenac Paramedics, the local paramedic service, later said they had treated 16 people at the scene — including three people with life-threatening injuries.
Frontenac OPP Const. Curtis Dick told CBC News that one person had died in the pileup, which involved at least one tractor-trailer. The person's name has not been released as next-of-kin were still being notified.
"We don't know the exact cause of [the pileup] yet. That's going to be a part of the investigation. We do have our traffic collision investigators — there's two [who] are going to be here for a period of time," Dick said from the scene of the crash Sunday evening.
"It will take some time for them to go through the scene, given the sheer number of vehicles."
As of 8 p.m. ET, the highway's westbound lanes were still closed. Dick said the lanes would not "realistically" reopen until Monday morning.
Stranded motorists not involved in the collision are being taken to a warming centre at the Rideau Heights Community Centre by Kingston Transit buses, police said.
Dick said people whose vehicles had to be towed to clear the scene should contact Frontenac OPP Monday morning to find out where they'd been taken.
The Kingston area is currently under a winter travel advisory, with as much as 15 centimetres of snow expected to fall along the shores of Lake Ontario by Sunday evening.
There were reports of heavy snow in the area at the time of the crash, said OPP spokesperson Bill Dickson.
Kingston police were also dealing with a gas leak after an afternoon collision at Princess and Macdonnell streets, a crash that Sgt. Steve Koopman said was also likely weather-related.
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