A woman was killed in a multi-vehicle collision on Highway 407 in Brampton on Tuesday afternoon that tied up traffic for hours.

Police shut down the westbound lanes near Bramalea Road after the collision late Tuesday morning.

Police said a piece of ice fell off a tractor-trailer and smashed the windshield of a white car.

The vehicle pulled over onto the shoulder, and as a tow truck operator was hooking up the vehicle, a black BMW lost control and rear-ended the tow truck.

The impact caused the BMW to roll over several times as it slid quite a distance down the highway. The driver of the tow truck, Allan McConnell, ran over to the BMW and tried to get the two female occupants out, but he said one of them died in his arms.

Shaken and in tears, McConnell said he wanted the victim's family to know he did everything he could do to save her.

"I'm very sorry about what's happened, but there wasn't anything I could do," he said.

McConnell said he himself was nearly killed in the crash as the BMW "missed me by three inches."

McConnell suffered minor cuts and scrapes, while the other female occupant in the BMW was taken to hospital with serious but unspecified injuries.

The stretch of highway remained closed until about 4 p.m., which caused extensive delays during the commute home.

Weather blamed in separate fatal crash

Blowing snow made driving difficult in areas north and west of Toronto on Tuesday morning, and the weather is believed to be the cause of at least one fatal accident.

One person was killed after a car and dump truck collided on Highway 47, near Uxbridge, just after 8 a.m. The roads were icy, police said.

Snow and ice also made for tricky driving along Highways 400 and 404. Police were called to dozens of accidents during the morning commute.

Police are urging motorists to slow down this winter season to prevent mishaps and serious crashes.

"The weather's been one factor, but speed's another major factor, and people are just not driving with care and caution as they should be," Durham region police Const. Al Ouellete told CTV News.

"It's the first couple of snowstorms we've had this year, and we're seeing a lot of spinouts."

As much as five centimetres of snow could fall on the Greater Toronto Area by day's end.

With reports from CTV's John Musselman and Roger Petersen