It's a nasty day to be driving in much of Ontario, thanks to fierce winds causing whiteout conditions on major roads and highways.

The occupants of at least 70 vehicles learned this the hard way around 10 a.m. on Monday, when a series of collisions forced the closure of Hwy. 400 near Barrie, Ontario.

Footage from the scene shows a mix of personal vehicles, transport trucks, and even a fuel tanker jumbled up together on the highway.

Multi vehicle pile up on #Hwy400 SB south of Mapleview #Barrie #PileUp #WinterStorm #WhiteOut pic.twitter.com/LYR8H9mlFt

— Sgt Kerry Schmidt (@OPP_HSD) February 25, 2019

Police say that both the north and southbound lanes of the busy highway will remain closed between Hwy. 89 and Mapleview Drive for "some time" as emergency crews tend to the wreckage.

"This is going to be a bit of a mess, getting this cleaned up," said  Ontario Provincial Police Sgt. Kerry Schmidt in a Periscope video at the scene. "It's going to be like this for a while."

UPDATE:ROAD CLOSURE: #Hwy400 is now CLOSED in both directions between Hwy 89 and Mapleview Dr #Barrie - Reopening time unknown. ^ag pic.twitter.com/ParB4XNbly

— OPP GTA Traffic (@OPP_GTATraffic) February 25, 2019

Ten people have reportedly been taken to hospital with minor injuries, though no serious injuries or deaths have been reported.

Barrie Fire announced on Twitter that a 500 litre deisel spill had occured as a result of the mass collision, but that it is now under control.

Update: 70+ vehicles involved, several tractor trailers. 500 litre deisel spill that is under control. Two @BarrieTransit busses on scene. @YorkParamedics multi-patient emergency support unit en route. Minor injuries reported. pic.twitter.com/yQNSRvrDwv

— Barrie Fire (@Barrie_Fire) February 25, 2019

Public transit buses have arrived to serve as warming stations, according to Barrie Fire, and some stranded motorists are being transported to the Georgian Downs racetrack.

Visibility remains near zero, according to Schmidt, as squalls continue to plague areas with lots of snow on the ground.

#Hwy400 at #Hwy93 OroMedonte Twp. Roads and weather status constantly changing. Please stay off the roads. #RoadClosures#RoadSafety#pjday ^cp pic.twitter.com/S7QvX2jSKs

— OPP Central (@OPP_CR) February 25, 2019

Police are asking motorists to stay off the roads in all of Simcoe County until weather conditions improve. Roads in both Wellington County and Dufferin County are closed until further notice.

As the OPP (and pretty much all Canadian cops, I think) like to say: "See snow? Go slow."

Solid advice on a day like this.