The National Transportation Safety Board (NTSB) has released hundreds of pages of documents from its investigation into last year’s fatal crash between a duck boat vehicle and a tour bus on Seattle’s Aurora Bridge. The duck boat crash killed five people and left many others with injuries.

On September 25, 2016, an amphibious duck boat vehicle owned by Ride the Ducks Seattle crossed over the double yellow line on the Aurora Bridge and broadsided a tour bus loaded with students from North Seattle College (NSC).

NSC chartered the bus to shuttle students and some faculty members from the school’s international program to an orientation at Safeco field. The deceased victims were all students aboard the tour bus, which was heavily damaged in the accident.

Eleven people aboard the duck boat were ejected from the vehicle. Sixteen people sustained serious injuries, and 20 others reported minor injuries in the accident. As for the tour bus, in addition to the five fatalities, 13 people aboard the bus sustained serious injuries.

What Is Included in an NTSB Report on the Tour Bus Accident?

As you may know, the NTSB is responsible for investigating transportation accidents and determining their probable cause (or causes). As part of the agency’s investigation, it releases Accident Investigative Dockets, which are essentially a collection of three reports:

Preliminary Report – A brief narrative and data describing what facts of the accident are known at the time. This report is usually issued a couple of weeks after an accident.

Factual Report – Documents created or acquired by the agency related to the investigation.

 Brief of Accident Report – A condensed report of basic facts related to the accident, including sequence of events leading to the accident, narrative and probable cause.

This week, the NTSB released its factual report on the duck boat crash in Seattle (the preliminary report on the accident was made available to the public last year). It contains not only facts and reports, but also still photographs captured from the front-facing video recorder on the tour bus. Video of the crash has not yet been released.

In a particularly unsettling image, you can see the duck boat vehicle swerving across the center line directly into the bus’s path less than a second before the collision. Other images in the NTSB report show how devastating the impact was. One photo taken from inside the chartered tour bus shows the 19’ by 6’ hole on the driver’s side of the bus, which is where some of the most significant injuries occurred.

Does the NTSB Report on the Seattle Duck Boat Crash Include New Information?

Yes, there are a couple of new issues included in the duck boat accident report that haven’t been discussed at length in media reports. The NTSB has been focusing much of its attention on a broken left front axle on the duck boat vehicle, which, in and of itself, isn’t new news. Something that hasn’t been widely reported, however, is the agency’s interview with the duck boat vehicle driver.

According to the report, the duck boat driver told investigators that he heard a “klunk klunk” sound as the vehicle drove over an expansion joint of the Aurora Bridge. At the time, the driver recalled thinking to himself that the sound was unusual. Seconds later, the duck boat vehicle made an un-commanded turn to the right, coming within a foot of hitting the wall that lines the side of the bridge.

As the duck boat driver attempted to correct the un-commanded turn and retain control of the vehicle, he noticed that the steering had become extremely loose. That’s when the duck boat vehicle veered to the left, directly into the path of the oncoming tour bus.

The driver said he tried to get the duck boat vehicle to turn again, but the steering was “locked.” He also said that the vehicle’s compression brakes would not stop, even though he was “standing” on the brake pedal.

The drivers of both vehicles told investigators that they had plenty of sleep the night before the accident, so fatigue is not believed to have been a factor. Alcohol or drugs do not appear to be a factor either, according to the NTSB docket.

As for the broken axle, investigators have closely examined an area where it joins, a part known as the steering knuckle. Photos from the report clearly show a broken joint at the steering knuckle, which may explain the duck boat driver’s struggle in maintaining control of the vehicle.

According to the NTSB, the type of duck boat vehicle involved in the accident differs from others operated by the Ride the Ducks franchise. The duck boat involved in the Seattle crash is known as a “stretch duck,” which is different in a number of ways from other ducks known as “truck ducks.”

Presently, Ride the Ducks Seattle only operate truck ducks, and there is good reason for that, according to King 5 News. In 2003, 2004 and twice in 2013, stretch ducks operated by other franchises were found to have cracked or broken axles.

A final report on the duck boat crash is expected to be released within the next few months. Along with the probable cause (or causes) of the accident, the NTSB will offer safety recommendations in an effort to make sure a disaster like this doesn’t happen again.