Crews are spending the night breaking apart a massive boulder that came crashing down on a stretch of highway near Port Alberni over the weekend.

The boulder, estimated to be about 10 feet by 10 feet and weighing up to 50 tonnes, toppled a tree as it came down on Highway 4 at Cameron Lake early Sunday morning.

No one was struck by the rock, which came to a stop on the shoulder of the highway.

“Where the rock originated from, it’s hard to tell. It’s very steep and a very high mountain here. It could’ve come from kilometres up the hill, it’s hard to say,” said Oliver Watson, operations manager for Emcon Services.

The tree was removed quickly, but due to its size, the rock was still in place Monday evening.

Watson said crews would use excavators and a rock hammer to break it up and haul it away.

Motorists should expect 20-minute delays up until midnight as crews work on the boulder. 

Many have already been slowing down as they drive past, stopping to snap photos, Watson said.

“There’s been a lot of people stopping to take pictures of the rock,” he said. “I didn’t realize that a rock was such a tourist attraction.”