An accident at the Port of Vancouver sent a massive crane toppling onto a cargo vessel early Monday morning.

The container ship was berthing when it "came into contact" with a ship-to-shore crane at around 4 a.m., according to the terminal operator.

The crane's boom came down on top of several shipping containers that were stacked seven high on the vessel, partially crushing some of them. The boom was left bent and warped with a mess of mangled yellow guard rails.

Global Container Terminals Vanterm told CTV News no one was injured and that staff alerted all necessary authorities about what happened.

"The vessel is currently being held alongside with tugs as the crane boom is on top of a container stack at the aft end," the company said in an email.

"While we continue to assess the situation, an exclusion zone has been set up to ensure the safety of all those at the terminal and for any operational impacts."

Video from CTV's Chopper 9 helicopter appeared to show crews responding from both land and water.

It's unclear what caused the accident or how long it could take to clear the scene, but structural engineer John Zickmantel said crews likely won't even get started "until the insurance gets settled."

"I’m sure they can bring in the equipment and get it done so the place can be used again in a week or two weeks, maybe, but it could take months," he said.

Zickmantel isn’t involved in the cleanup, but said if he were, one of the first tasks would be to ensure the boat and crane are stable to prevent further damage.

"The part that's fallen down, that just has to be taken off of the boat somehow, maybe with a bigger crane or in pieces … get some torches and burn it off," he said.

The container ship involved is marked as the Ever Summit, a Panamanian cargo vessel that was scheduled to arrive at the port at around 3:15 a.m. Monday.

The Port of Vancouver directed questions about the incident to GCT Vanterm.

With files from CTV Vancouver's Ben Miljure