A big mess of smashed vehicles at the south end of the Overlanders Bridge Saturday afternoon could've been avoided if drivers had been more attentive to road conditions, says RCMP.

As it stands, however, none of the 12 drivers involved in two separate although related crashes will face charges.

It all started just after 1:30 p.m. when a driver screeched to a stop when he noticed two vehicles ahead of him had crashed.

That triggered a domino effect that ended with 10 vehicles rear-ending each other behind him.

Four people were taken by ambulance to Royal Inland Hospital for treatment of minor injuries, four vehicles were towed away and the rest of the drivers were able to drive their vehicles home.

Five RCMP officers shut down two bridge lanes for an hour to clean up the mess.

None of the drivers are facing charges because "it's too difficult to determine who is at fault there," said Staff Sgt. Dave Prentice.

"There are no independent witnesses that we know of, just a whole lot of things colliding with each other and difficult to pin blame on any one person."

And it's unclear what started the chain reaction in the first place.

"The people involved in the original accident exchanged information and left without supplying any information to the other 10 cars," said Prentice.

What is clear, he said, is that the mess could've been avoided.

"Hopefully we all realize that snow and ice are slippery just like it is every time this year. And perhaps early in the season when it's usually snow of the wet variety, which makes stopping that much more difficult, it will remind everybody that we recommend snow tires and to slow down, keep their distance from the vehicle in front of them and arrive safely to their destination."