NTSB investigating fiery Tesla crash that killed driver | News | Mountain View Online |


NTSB investigating fiery Tesla crash that killed driver

Tesla officials say missing crash barrier likely to blame for crash's severity

The National Transportation Safety Board is investigating the fiery car crash on Highway 101 that killed the driver of a Tesla Model X last Friday. On Tuesday, Tesla officials blamed the severity of the crash on a missing protective freeway barrier, called a crash attenuator, and announced that the company also is investigating the accident.

San Mateo resident Wei Huang, 38, was identified by the Santa Clara County medical examiner's office as the driver who later died of his injuries after his Tesla collided with a median at freeway speeds, triggering a three-vehicle accident and causing the car to catch fire.

The NTSB announced over social media Tuesday morning, March 27, that the agency is investigating the fatal crash and the emergency response from the Mountain View Fire Department.

The crash occurred around 9:30 a.m. March 23, when the Tesla Model X struck the barrier separating the Highway 85 carpool flyover lane from southbound Highway 101, according to California Highway Patrol officials. The Tesla careened into two lanes of Highway 101, where it was struck by a Mazda and then an Audi. Huang was transported to Stanford Hospital, where he died of his injuries later that day.

Emergency fire crews arrived at the crash shortly after 9:30 a.m. and found that the front end of the Tesla had "substantial damage," exposing the vehicle's lithium ion battery and causing it to catch fire, according to Mountain View Fire Chief Juan Diaz.

In a blog post Tuesday, Tesla officials stated that the company is "deeply saddened" by the fatal accident, and is assisting in the investigation. The vehicle's logs, which could provide a window into what happened leading up to the crash, have not been retrieved yet due to the "extensive damage" of the collision, according to the statement.

The blog claims that the damage to the Model X was so severe because the attenuator barrier -- a safety barrier that divides the highway from the carpool flyover -- had "either been removed or crushed" in a prior collision and had never been fully replaced, leaving little cushion between the tip of the barrier and the cement median.

"We have never seen this level of damage to a Model X in any other crash," according to the company statement.

Caltrans, in an emailed response to the Voice's query, did not directly answer questions about the the attenuator barrier.

"We are reviewing the facts and circumstances of this incident and are cooperating with the National Transportation Safety Board’s ongoing investigation. Safety is our top priority and Caltrans will carefully evaluate the investigation’s findings and take appropriate action," Robert Haus, chief spokesman for Caltrans District 4, said in the email.

Tesla vehicle batteries are designed to prevent fires from occurring rapidly, giving occupants time to get out safely, and witnesses at the scene of the crash reported that no occupants were in the Model X when it caught fire, according to the post.

Electric vehicle fires are typically put out by blasting a large quantity of water -- 3,000 gallons -- directly on the battery to bring down the temperature of the cells, which can overheat and reach temperatures of up to 900 degrees, said fire Chief Diaz.

Diaz said the department was put in a difficult situation. Fire crews had 500 gallons of water at the scene, but getting any more would have required running 2,000 feet of thick fire hose across Highway 101, which would have been catastrophic for traffic in both directions, Diaz told the Voice. But letting the car continue to burn on a busy highway, destroying the battery, would have been a bad choice as well, he said.

"In the middle of the Highway 101 freeway, that's not something we want to do," he said. "And it's not good for the environment with the byproducts of combustion."

Fire crews used the available supply of water and contacted the manufacturer of the vehicle, Palo Alto-based Tesla, to assist in getting the battery's temperature under control. Diaz said the engineers essentially disassembled a portion of the car battery on the spot, and that subsequent thermal imaging showed that the battery was no longer unstable.

Fire engines escorted the tow truck that removed the Tesla all the way to the impound yard out of an abundance of caution, Diaz said. Car batteries are capable of reigniting for 24 hours after cooling.

The challenging situation was made worse by the significant damage caused by collision itself. Diaz said that Tesla vehicles are built to be very safe, with features to help first responders deal with lithium ion batteries that ignite, but in this case emergency crews had no access to the battery's disconnect wires because they were destroyed on impact. This is the first time the department has dealt with this kind of problem, Diaz said, and he commended his department's response to the dangerous situation.

"I'm frankly very proud of how the Mountain View firefighters handled the event," he said.

NTSB spokesman Christopher O'Neil told the Voice that the two investigators assigned to the incident came to Mountain View on Tuesday to conduct what the agency calls a "field investigation" of the crash, which is narrow in scope and examines specific safety issues rather than an all-encompassing accident investigation.

"It's going to focus on the post-crash fire that resulted in this accident, and steps that were taken and necessary to make the vehicle safe for removal from the scene," O'Neil said.

It's unclear whether the Telsa's automated control system aboard the vehicle was active at the time of the crash. According to Tesla's blog post, its "Autopilot" system has been engaged roughly 85,000 times on the same stretch of road since 2015, and company representatives aren't aware of any accidents. "There are over 200 successful Autopilot trips per day on this exact stretch of road," the post said.

NTSB investigative teams typically spend about five to 10 days working at the scene of the crash, depending on the complexity of the incident, before starting work on publishing the results. O'Neil said the investigation may or may not lead to a preliminary report a few weeks after reviewing the accident, and it's possible the accident report will be rolled into a larger investigative review of similar accidents.

O'Neil said reports on car batteries and the appropriate response to incidents like the accident on Friday are important, given that electric cars are increasingly common on roadways and emergency responders need a good strategy to render the vehicles safe. He said the report is not aimed at affixing blame or liability on the fire department or any of the involved parties, instead taking a close look at what could be done to help save lives and mitigate the effects of the accident.

"The report looks at whether there's something that could be done or should be done," he said. "It's not that we think there's a problem, it's that we want to explore that issue."

Tesla representatives did not respond to requests for comment.

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5 people like this
Posted by South los altos resident
a resident of another community
on Mar 28, 2018 at 12:34 pm

My thoughts and prayers to the family. I drove the 101 north off of 85 that morning, about 10-15 minutes after the Tesla X crash 3/23. Freeway was jammed all the way back from palo alto/menlo coming south. I couldn't help but see the horrific scene in the slow moving traffic. The harsh reality of what 101 on the peninsula has become over the years is there is hardly any median. Driving in the left lane where concrete barriers are near and sometimes on the left lane line itself will cause more accidents to happen. The only thing a driver can do practically is be super cautious in left lanes when they get that tight.

As for what happened to the X, I hope they do find all reasons (how much was driver related vs the car itself). Those things have been tested an insane amount. Because it has batteries and it has cutting edge driver assist features the media will be super focused about it, and understandably so. As for the auto-pilot, it should be investigated, but Ive driven these cars and loaners and if anything they are too conservative and won't activate in rush hour traffic like this.

If there is a car influenced factor to this is should obviously be dealt with.

4 people like this
Posted by Dashcam
a resident of Old Mountain View
on Mar 28, 2018 at 1:36 pm

Seems like they could verify the claims about the missing barrier by putting out a call for dashcam footage from anyone who drove by the area just before the crash.

7 people like this
Posted by let'sgetreal
a resident of Blossom Valley
on Mar 28, 2018 at 5:00 pm

I was just driving that route today. Those cement barriers are ominous! I'm extremely careful, and do not drive in the fast lane, anywhere near the barriers. Drivers were driving 75 - 80 mph!! Just not worth driving so fast when there's so much at stake.

13 people like this
Posted by Drury
a resident of Willowgate
on Mar 28, 2018 at 5:40 pm

Curious. Google earth shows about 20 ft of crushable barrier and the crash photo shows the crushed barrier.

Why would Telsa suggest an invalid excuse?

5 people like this
Posted by First Of All
a resident of Castro City
on Mar 29, 2018 at 9:47 am

FIRST OF ALL, they got the model of the car wrong. It's not a model X, it's a MODEL S. As you can clearly see in the picture.

3 people like this
Posted by Steven Nelson
a resident of Cuesta Park
on Mar 29, 2018 at 10:21 am

Steven Nelson is a registered user.

Inadequate crash barrier for 65 MPH (or greater) into a fixed cement abutment? I too looked at the Google Street View of what I think is this particular left-lane freeway divider. (thanks @Drury of Willowgate)

Web Link

There definitely is a crushable barrier in front of the fixed cement. However it only appears, maybe, 12 feet long. It may be that this is totally inadequate for a crash at full speed into an 'abrupt stop'. (Note that the concrete is not allowing the car, truck, or bus to slide over the concrete barrier - it must plow directly into the concrete once it crushes the barrier.

This type of "hard-stop" in the medians/exits of freeways has led to deaths in South San Jose (large bus accident) or into giant hard-poles in other parts of the US and Calif (also large bus).

Simple physics experiments have now been done - results, deaths. The NTSB report on the San Jose freeway bus deaths found that CalTrans was responsible for inadequate design of the median barriers.

So, I think this is what Tesla may be claiming. Inadequacy, not non existence.

3 people like this
Posted by Steven Nelson
a resident of Cuesta Park
on Mar 29, 2018 at 10:30 am

Steven Nelson is a registered user.

BTY - the Google Street View (c) is marked as Nov 2017, so 'the crowd-sourced dash cam' idea would be great as an independent verification of a crushed/damaged metal barrier. CalTRAN public documents should also show evidence of this damaged condition (as the lawyers of the family of the cash victim will surely request).

Reporter Kevin, time for a Voice PRA request of CalTRAN?

3 people like this
Posted by tootsieburpee
a resident of Another Mountain View Neighborhood
on Apr 18, 2018 at 8:38 am

tootsieburpee is a registered user.

[Post removed due to promoting a website]

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