If you need to take Highway 400 any time soon, expect significant traffic delays.
UPDATE: Police tweeted at 1:30 p.m. that all roadways have reopened.
EARLIER: The highway is closed between Finch and Highway 401 due to an issue at a fertilizer plant that's resulted in "potentially highly toxic fumes," according to Toronto Fire, and people are being warned to avoid the area.
The smoke can be seen in this video taken at 11:00 a.m. on Wednesday morning — OPP confirmed that the Arrow Road and Highway 400 area is being evacuated.
The 400 has been closed in both directions, and the TTC has tweeted that "significant" delays to bus service are expected.
Ontario 511 highway cams also show that traffic is backed up to an intense degree while Toronto Fire and Toronto Police continue their investigation.