Amphibious vehicles have been investigated for their involvement in serious collisions before, but not on land.

On Friday, the National Transportation Safety Board started its investigation of Thursday’s fatal crash involving a charter bus and Ride the Ducks vehicle on Aurora Bridge. Board member Earl Weener said there could be some unknowns.

“We have not investigated an amphibious vehicle on land,” he explained. There have been “several” investigations on water.

Photos from the scene of the crash

The investigation, then, is a new aspect for the NTSB team to study. The team arrived in Seattle Friday morning to begin what could be up to a year’s worth of work.

“This is a major investigation as far as we’re concerned,” Weener said.

Though the NTSB team will study all aspects of the crash, including the bridge itself, there is a particular interest in studying the charter bus. There have been a number of fatal crashes involving buses in the past, which has included the strength of things such as roofs and windows, Weener explained.

The NTSB’s job is not to place blame. It is to help improve safety. Should the team find anything of concern before its investigation is complete, it could put out “urgent recommendations,” Weener said.

As of Friday afternoon, however, the NTSB was just getting settled in for what could be a long investigation.

Crash victims identified

The identities of three of the victims from Thursday’s fatal collision on the Aurora Bridge were released.

• Claudia Derschmidt, 49, of Austria

• Privaudo Putradauto, 18, male, of Indonesia

• Mami Sato, 37, of Japan

Seattle officials are not releasing information about a fourth victim, a 17-year-old girl from China. Her family has been notified, but since the student was a minor, the school is keeping her information private.

“It’s important that we know that this tragedy has faces, and has stories,” said North Seattle College President Dr. Warren Brown. “These are students we will miss here at North Seattle College.”

“At North Seattle College, there are still wounds in our hearts and it’s going to take a while for our students as staff here to get through that,” he said.

Derschmidt was just starting in the international program at North Seattle College. She had brought her 15-year-old son with her to the United States. He was on the bus with her.

An employee, who spoke German, with the Seattle Department of Transportation was called to the scene. They served as translator between emergency crews and the 15-year-old Austrian.

Investigation

The Aurora Bridge was reopened Thursday night, 12 hours after the collision.

There are two cameras on Ride the Ducks vehicles. The company is providing access to vehicle video during the crash to help with the investigation.

“The NTSB investigation will really help us to understand whether it was the structure itself [that caused the crash], versus the vehicles or a combination of the two,” Mayor Ed Murray said Friday morning.

“[Thursday] night, they finally got the bus and the Ride the Duck vehicle off the bridge on big platform trucks,” Kerns said. “They’ve taken them to a local warehouse. The first thing will be to investigate the Duck bus.”

Investigators with the Washington State Department of Transportation reportedly have said the Aurora Bridge is safe to cross after the accident.

“Overnight WSDOT had a chance to inspect the bridge, they now tell us, ‘No damage,'” said KING 5’s Jake Whittenberg. “We also learn today that the NTSB federal investigators will arrive this morning. They will investigate the wreckage in a DOT garage in south Seattle.”

The Ride the Ducks fleet has been shut down voluntarily as the investigation into the crash continues.

The charter bus and a Ride the Ducks vehicle collided at around 11 a.m. Thursday. The bus was carrying students that were part of a foreign student program at North Seattle College. They were on an orientation and visiting local sights such as Safeco Field. The students are from China, Japan, Indonesia and Austria.

“I’ve never seen carnage like that before. I’m thankful to be alive and I’m glad my wife is alright as well,” said Tim Gesner, who was on the Duck vehicle with his wife during the crash.

“As I turned my head I heard the driver say ‘oh no,'” he told KING 5 of the events leading up to the collision.

Gesner only suffered a soar neck and back. After the crash he quickly began helping others until emergency crews arrived.

“I’ve never seen such an organized effort, these people knew what they were doing,” he said of the crews on the scene.

The Seattle Fire Department reports 12 people suffered critical injuries. More than 50 people were sent to area hospitals, with 30 people that had various minor injuries, according to Harold Scoggins chief of the Seattle Fire Department. People with the most serious injuries were sent to Harborview Medical Center.

What happened

Rujia Xie was among the North Seattle College students on the bus, en route to Seattle’s Pike Place Market and Safeco Field when the accident happened. She heard the crash from the back of the bus, then smelled gas. Glass fell on to her face. She was able to jump out of the bus after the collision, the Associated Press reports.

Mixon said a total of 45 students and staff were on the bus.

In the Ride the Ducks vehicle, traveling in the opposite direction, were three dozen passengers and the driver.

Witnesses report that the Duck vehicle suddenly veered into the side of the bus as it passed.

People were then seen “flying” when the two vehicles collided, KIRO Radio’s Josh Kerns reports.

Related: Blood bank seeks donors after fatal Aurora Bridge crash

Though the exact cause of the crash is not known, Kerns overheard one tourist say that a tire on the Duck blew, causing the vehicle to crash into the side of the bus. There were two other passenger vehicles involved.

“A number of eye witnesses said that it appeared that the duck vehicle suffered a blowout or some sort of mechanical malfunction with the left front tire…all of a sudden it was as if the driver veered to the left,” Kerns said, noting that another witness said that they saw the wheel lock up first, perhaps implying that a mechanical issue could be a cause.

Ride the Ducks of Seattle has suspended its operations for the rest of the day, KING 5 reports.

Emergency response

“Yesterday was one of our busiest days,” said Susan Gregg with Harborview Medical Center where many of the crash victims were taken.

“We are the level one trauma center for four states,” she said. “And there is a reason for that. We know what we are doing.”

A total of 17 people came into Harborview initially. Three people went straight to an operating room. The hospital has 15 patients from the collision; 11 remain in intensive care with one being in critical condition, and 10 in serious condition. Three patients are now out of the intensive care unit.

About 90 Seattle firefighters and medics responded. People were being removed from the Duck vehicle through a broken window, Kerns reports. There are no seat belts on board.

Witnesses recount the crash

One witness to the crash said she saw people sprawled on the pavement or walking around in shock. Another said he heard a screech and the sound of metal crashing into metal and soon saw several people on the ground.

After the crash, there was a steady stream of ambulances to transport people to local hospitals.

Statement from Ride the Ducks

Brian Tracey, president of Ride the Ducks, told KIRO 7 that safety is a top priority and the company’s drivers are constantly training. He did not know how the crash happened, but said the company is fully cooperating with investigators.

Not the first crash

Thursday’s collision was not the first such incident involving a Ride the Ducks vehicle in recent time. In June, a vehicle struck a pedestrian in a non-fatal collision. A lawsuit was settled involving a motorcyclists who alleges one of the vehicles ran him over and dragged him down the street in 2011.

Elsewhere, 13 people drowned in a 1999 incident in Arkansas involving a similar amphibious vehicle, however, it was not associated with the Ride the Ducks company. In 2010, a Ride the Ducks vehicle was run over by a tugboat in Philadelphia. Two people were killed in that collision. The tugboat captain was on his cellphone at the time of the crash.