Six people were rushed to hospital Monday — two of them with serious injuries — after a massive collision that involved numerous cars and trucks on the Trans-Canada Highway on Newfoundland's west coast.

The 15-vehicle pileup included three tractor-trailers.

This is why the TCH is closed near Birchy Lake. Police escorted me onto the scene. 15 vehicles involved including two tractor trailers. Six people taken to hospital, two with serious injuries. Tow trucks are close to clearing one lane at this point. <a href="https://twitter.com/CBCNL?ref_src=twsrc%5Etfw">@CBCNL</a> <a href="https://t.co/3z37ZrSzVb">pic.twitter.com/3z37ZrSzVb</a> —@JenniferGrudic

Four of the six people taken to hospital have injuries that are not thought to put their lives at risk, the RCMP said early Monday afternoon.

The TCH near Birchy Narrows was closed around 10:45 a.m.

Up to eight ambulances responded to the scene, in addition to police officers from three different detachments and fire fighters from three different municipalities.

Traffic had been backed up at least half a kilometre.

Shortly after 4 p.m., one lane of the highway had re-opened to traffic. But police warned drivers that whiteout conditions and high winds were ongoing and to expect delays.

Tow trucks have not yet arrived to the crash site, police said.

RCMP Cpl. Jolene Garland told CBC Radio's On The Go it was one of, if not the biggest, traffic pileups she can remember.

She said while the investigation is continuing into exactly what caused it, the whiteout conditions and high winds are likely major contributing factors.

Police closed the road far back from where the accident actually happened because there are bad whiteout conditions further up the highway. Hard to imagine when the sun is shining here. <a href="https://t.co/No1mEe8udt">pic.twitter.com/No1mEe8udt</a> —@JenniferGrudic

Read more articles from CBC Newfoundland and Labrador