VANCOUVER -- Crews are searching for a person reported missing along the Capilano River after the Cleveland Dam released a flood of water Thursday afternoon.

Several people were swept away in the torrent of water that unexpectedly released from the dam around 1:30 p.m., and one man was killed. 

Police confirmed two people were able to get to safety on their own, while two others were rescued from the water.

On Thursday evening, authorities said they were not able to rule out whether anyone else had been swept away. There were many people fishing along the river when the water level rose suddenly.

North Shore Rescue said one person has since been reported missing to RCMP.

The volunteer team returned to the river Friday to search, using a helicopter and volunteers in kayaks to check the lower river, where the missing person was last seen.

“My understanding is he was a fisher in the river just below the highway bridge. So that is the point last seen, so we’re searching from there down,” North Shore Rescue search manager Allan McMordie told CTV News.

So far, the team has not been able to find any sign of that missing person.

In an update Friday afternoon, North Vancouver RCMP said North Shore Rescue had concluded its search of the river up to its mouth, where it enters the Burrard Inlet. No additional victims were found.

Boats from the RCMP and the Vancouver Police Department are now searching the waters beyond the mouth of the river, and the RCMP Underwater Recovery Team has been called in to assist in the search, police said.

In statements posted on social media, Metro Vancouver said the dam's spillway gate released "a large volume of water" during maintenance. The regional authority said the problem was resolved in the afternoon and that a full investigation had been launched.

Metro Vancouver commissioner Jerry Dobrovolny offered similar comments when speaking to media Thursday afternoon.

"Certainly it is a very serious matter," he said. "We are very concerned about what happened and it affected a great number of people and the investigation will leave no stone unturned."

He could not say if officials believed the issue was human error, a mechanical problem, or something else.

Readings on the Metro Vancouver website give an indication of how rapidly the river surged on Thursday. They show the water level suddenly rising from about 0.6 metres up to 4.2 metres before dropping down again just as quickly.

The water flow simultaneously sped up, reaching 400 cubic metres per second before returning back to normal.