A passenger ferry carrying hundreds of people ran aground near Bainbridge Island west of Seattle but there were no reports of injuries or contamination, authorities have said.

The Walla Walla ran aground in Rich Passage at around 4.30pm local time as it was travelling from the city of Bremerton to Seattle, according to Washington State Ferries, a division of the state Department of Transportation.

“Initial indications are the vessel suffered a generator failure,” but investigators were still looking into what happened, the agency said.

Passenger Haley Socha told The Seattle Times that the ferry’s lights went out about 20 minutes into the voyage and the engines stopped.

People stand on the shore while looking at the Walla Walla passenger ferry after it ran aground near Bainbridge Island west of Seattle
People stand on the shore while looking at the Walla Walla passenger ferry after it ran aground near Bainbridge Island west of Seattle (Meegan M Reid/Kitsap Sun via AP)

The lights came back on after a minute and there was an alarm and an announcement saying the vessel had no propulsion and warning people to brace for impact.

People helped one another as they donned life vests, Ms Socha said.

“Everybody’s been really nice and good to each other,” Ms Socha told the Times.

There were 596 passengers and 15 crew members aboard, according to ferries spokesperson Diane Rhodes.

A tug boat and the Coast Guard were on the scene.

“Vessel engineers believe tide will be at the right height to safely tow the boat at midnight. We apologise to passengers. Their safety is our first priority,” Washington State Ferries said via Twitter.

Passengers were initially kept onboard.

One passenger suffered a medical emergency unrelated to the grounding and necessitated an evacuation, the agency said.

In this photo posted to social media by the US Coast Guard, a crew member stands by ready to assist as emergency personnel respond to the Walla Walla passenger ferry, background right, which ran aground near Bainbridge Island west of Seattle
In this photo posted to social media by the US Coast Guard, a crew member stands by ready to assist as emergency personnel respond to the Walla Walla passenger ferry, background right, which ran aground near Bainbridge Island west of Seattle (US Coast Guard via AP)

At around 8pm, Kitsap Transit began taking others off the boat, ferry officials said.

The transit agency deployed two passenger-only vessels, the Commander and the Waterman, with respective capacities of 250 and 150 passengers, requiring multiple trips to the Walla Walla.

Kitsap Transit reported the Commander had delivered the first load of people to the slip at Bremerton.

“We’re working on a plan for the vehicles onboard so passengers can retrieve them tomorrow,” Washington State Ferries said.

A photo taken by a Coast Guard officer showed the Walla Walla near the shore as people looked at it from the beach and snapped pictures.

A tug was positioned at one end of the ferry with an apparent Coast Guard boat nearby.

“No pollution or hull damage detected at this time,” the state Department of Ecology reported.

“Ecology responders on the way to the scene.”

Passengers aboard the Walla Walla passenger ferry gather on the bow after the vessel ran aground near Bainbridge Island west of Seattle
Passengers aboard the Walla Walla passenger ferry gather on the bow after the vessel ran aground near Bainbridge Island west of Seattle (Meegan M Reid/Kitsap Sun via AP)

The Seattle-Bremerton route was out of service until further notice, the Department of Transportation said on its website.

The website lists the Walla Walla as a four-engine, jumbo class ferry with a maximum capacity of 2,000 passengers and 188 vehicles.

It is 440ft (134 metres) in length with a draft of 18ft (5.4 metres).

The Walla Walla was constructed in 1973 in Seattle and rebuilt in 2003, according to the site.