An Ontario Provincial Police cruiser is seen in this undated photo. X/OPP
A portion of the westbound Highway 401 that was closed in Whitby after a collision has partially reopened.
A transport truck was involved in a crash leading to a diesel spill.
The westbound 401 was closed at Brock Street and the Consumers Drive on-ramp to the westbound 401 was also closed. The right lane at Brock Street has since reopened to traffic but the two left lanes remained closed.
The OPP says drivers can re-enter the highway using the Brock Street on-ramp.
Clean up efforts are expected to take between four to six hours.