A stretch of Bayview Avenue is closed in Thornhill after a water main break opened up a massive sinkhole in the middle of the road early Friday morning.
A large section of the road collapsed around 3:30 a.m. because of flooding along portions of Bayview and John Street, north of Steeles Avenue.
Northbound Bayview is closed at Steeles, while the southbound lanes are blocked at John.
Commuters are bracing for a major traffic disruption because York Region officials believe the road or sections of it may be closed for up to a week while emergency repairs are made. The road is a major artery for people who commute to and from Toronto.
All lanes are expected to be closed through the weekend and Monday morning's commute. Motorists are asked to use Yonge Street or Leslie Street as an alternate route.
YRT/Viva's 91 and 91A buses are diverting around the closure.
York Regional Police said water gushed from the broken 30-centimetre pipe on John, just west of Bayview, for about four hours.
The ground became soaked and soft, causing the section of road to buckle and create a sinkhole more than 10 metres deep.
Two places of worship and three homes were without water until just before 5 p.m.
"Our next big task is to fill in the hole and fix up the road," Peter Loukes of Markham Waterworks told CP24. "We are in the midst of backfilling right now."
In the Greater Toronto Area, the average water main is about 55 years old, while some are 80 to 100 years old. Age and the freeze-thaw cycle are usually to blame for water main breaks.
Click here to view a photo gallery of the sinkhole and flooding.
With a report from CP24's George Lagogianes
