A water main break outside the Vancouver Art Gallery caused a traffic nightmare in the heart of downtown Monday.

At about 6 p.m. on West Georgia at Hornby streets, rush hour traffic had to be diverted after water began pouring out of a crack in the road. 

"We see this water bubbling up through the ground. Now we're thinking 'oh my god, it's going to create a sinkhole because it's a lot of water coming up,'" said Patrick Stewart, a witness.

Water and debris shot several hundred metres into the air.

"Rocks! We're in the splash zone," Stewart told CTV News Vancouver just steps away from the action. 

The massive stream could be seen from blocks away.

"It's crazy we saw it from down there and we thought it was like a fire hose going," said Eryn Vanvloten, another witness.

A food truck was parked right next to the break. Staff said they heard a loud bang moments before the flooding started. 

"I've been in this spot all summer and never seen anything like this and it's sad because way too much water wasted," said Felipe Coutinho, who runs the truck.

Coutinho was forced to close early because of all the commotion.

The steel piping is nearly a century old. 

"It's just old infrastructure that's in need of repair we're planning to repair this main sometime in the first half of next year, but it didn't last as long as we wanted," said Daniel Roberge, director of water and sewers for the City of Vancouver.

The transmission water line is a major part of the city's water network.

"It supplies a large portion of downtown, there will be some residents with lower water pressure," Roberge told CTV News.

He believes the burst may have been caused by the weather.

"A change in temperature there's contraction in the pipes and it's usually a little bit worse at this time of year," explained Roberge.

Large pools of water formed in the surrounding area, but the city says the art gallery did not sustain any damage.

Crews worked through the night into Tuesday to repair the water main, but eastbound lanes on West Georgia and the surrounding sidewalk were still closed. Both are expected to be blocked until at least mid-Tuesday morning.