A woman is dead after her sport utility vehicle crashed on Highway 404 in Markham Sunday morning, Ontario Provincial Police say.

Police said the white Mercedes-Benz SUV crashed in the southbound lanes of the highway near Stouffville Road around 9:30 a.m.

The female driver was pronounced dead at the scene, police said.

Another vehicle went into a ditch when it swerved to try and avoid the rolling vehicle.

All southbound lanes and one northbound lane of Highway 404 were shut down between Stouffville Road and Elgin Mills Road as police investigated the fatal collision. The road reopened shortly before 1:30 p.m.

The reason for the rollover is not yet known. Police are investigating the fatal crash.

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