The so-called duck boat was ferrying tourists across a crowded Seattle bridge when the amphibious vehicle suddenly swerved into an oncoming charter bus carrying foreign exchange students on their way to an orientation event.
The resulting crash killed four students, injured dozens of others and raised safety questions about the distinctive former military vehicles popular with tour groups across the country.
Rujia Xie and other North Seattle College students were on their way to the city's iconic Pike Place Market and Safeco Field on Thursday when she heard the crash from the back of the bus.
She smelled gas and felt glass falling on her face. She and others jumped from the bus.
Traveling in the opposite direction, two Philadelphia friends on a cross-country road trip, Brad Volm and Bradley Sawhill, were cruising over picturesque Lake Union when they said they saw the duck boat's left tire lock up as it swerved into the charter bus, T-boning it. Their SUV hit another truck head-on, but they escaped injury.
"It all happened so fast. I got out of my car, and there were just bodies, just everywhere. People lying in the street," Volm said.
The military-style tour vehicle that can also be operated on water belongs to a tour company called Ride the Ducks, which offers tours known for exuberant drivers and guides who play loud music and quack through speakers as they lead tourists around the city.
The collision on the Aurora Bridge, which carries one of the city's main north-south highways over the lake, left a tangled mess of twisted metal, shattered glass and blood, witnesses said.
The four North Seattle College students killed in the crash were from Austria, China, Indonesia and Japan, the school said Friday. Efforts are underway to contact their consulates.
College spokeswoman Melissa Mixon said 45 students and staff were on one of two charter buses traveling downtown. Students, faculty and staff of the diverse college of about 14,000 students gathered on campus Friday morning to grieve, she said.
"Sad doesn't even begin to describe how people feel," she said.
Authorities say 51 people were taken to area hospitals. Susan Gregg, a spokeswoman for Harborview Medical Center, said in a statement early Friday that one person is in critical condition and 11 are in serious condition in intensive care, Gregg said. Three others are in satisfactory condition.
At the University of Washington Medical Center, two people are in serious condition, and two others are in satisfactory condition at Northwest Hospital & Medical Center, Gregg said.
The stretch of highway where the accident took place reopened for traffic late Thursday. The National Transportation Safety Board sent a 17-person team to Seattle that would take over the investigation.
There was no immediate word about the cause of the crash, but initial reports described the accident as a head-on collision.
Three dozen people were on board the amphibious vehicle, as well as the driver, who is certified by the Coast Guard and a licensed commercial driver, company President Brian Tracey said. He said he did not know what caused the crash.
"We will get to the bottom of it," he told The Associated Press. "Our main concern right now is with the families of those hurt and killed."
Mayor Ed Murray said the company had taken the duck boats off city streets for now.
Tourists aboard the duck boat told reporters they were snapping pictures when they were thrown from the vehicle.
Lying in his hospital bed, Tim Gesner, 61, of Orlando, Florida, told The Seattle Times that he was standing in the back of the duck boat, trying to take a picture. He felt the vehicle start to fish-tail, and the driver said, "Oh, no." Gesner looked forward and saw the duck boat veering left, directly into the bus.
"Then next thing was it's like you see in the movies," he told the newspaper. "I was floating in this surreal world, like I was in slow motion bouncing off of things and just feeling the pain shooting everywhere and then my face slamming against the seat in front of me and then it was quiet."