*Update: Fourth Line has now been reopened.*
Emergency services are on the scene at a single vehicle crash in rural Halton Hills this morning, which police say has ruptured a high-pressure gas line.
Fourth Line between 17 and 22 Sideroads, just outside Acton is closed as a result of the collision.
Police say Enbridge Gas is attending, and nearby homes have been evacuated.
Local drivers are being asked to avoid the area and choose an alternate route.