Checking in on CNG: Accidents Will Happen

According to the Daily Breeze, the owner-driver of a SuperShuttle van was killed while refueling at a CNG (compressed natural gas) station in Carson yesterday. Bob Mancuso, 61, was thrown 30 feet by the powerful explosion. There’s no photo to illustrate the story, but the writer describes the back of the van as “twisted out of shape” and the fueling station as littered with “shards of metal and plastic.” It sounds lucky that more people weren’t killed or hurt.

Why did this happen?

Sheriff’s investigators do not know the cause of the 10 a.m. incident, but Mancuso’s wife, Dianne, said her husband had been rear-ended by a drunken driver earlier in the month and had just gotten the vehicle back from the repair shop the night before.

“He got the van back last night and was told everything was OK,” she said.

“It’s not something anybody would ever expect,” she said a few hours after the blast.


Digging around the web for information on CNG, I was a little surprised at the circumstances of this accident. The potential for a deadly accident if a CNG tank is punctured is well-known. I’d be curious what procedures SuperShuttle follows after one of its franchisees is rear-ended to ensure that the fuel tank is not compromised. Does SuperShuttle have an authorized repair shop? Since the franchisee owns and operates his or her vehicle, there’s no revenue coming in if the van’s in the shop. Does that create a perverse incentive to turn around repairs too rapidly?

In the story, Mancuso does not come off as a careless man.

Although a smoker, Mancuso would never hold a lit cigarette while filling the tank, his wife said.

“He had the highest respect for that fuel,” she said. “My husband is stubborn, but he had a lot of respect. That is something you don’t play around with.”

CNG is one of the alternative fuels that began to gain acceptance in the late 1980s as a cleaner alternative to gasoline and diesel. I seem to recall SuperShuttle making a lot of noise about its switch to CNG here locally, but the company’s current website makes no environmental boasts.

The firm was purchased by Veolia Transportation in a deal announced last October. Veolia, which was previously known at Connex, also runs the Metrolink rail service in LA. It’s a subsidiary of the France-based Veolia Environment, which itself was a spin-off from Vivendi. Veolia Environment’s tagline is “The Industry of the Environment.” They’re involved in a number of environmental concerns around the world, but I couldn’t find any specific reference to CNG.

I did look up “CNG accidents” however, and found this horrific story from India, where many of the buses run on CNG:

Ahmedabad, May 15 (PTI): The number of dead in yesterday’s collision between a CNG-run state transport bus and a chemical tanker in Anand district rose to 29 today, police said here.

A total of 29 bodies have been recovered so far and police have been able to identify six of them. They include four women and drivers of the bus and the tanker.

Fourteen people were injured in the accident.

Most of the victims were charred beyond recognition, police said.

The mishap occurred when the bus which was headed towards Vadodara on national highway number eight in Anand district hit the chemical tanker while trying to overtake.

This might be a good time for whatever companies market CNG, CNG fuel tanks, and CNG-powered vehicles to take a look at whether they’re doing all they can to safeguard the public. Are the operators of CNG vehicles properly educated for safety? Are the repair requirements sufficiently stringent? Are the tanks as safe as they can be, given the catastrophic result if they are breached?

CNG is a cleaner-burning, domestically available fuel that will probably get renewed attention as all the presidential candidates campaign for U.S. energy independence and reduced greenhouse gas emissions. When the spotlight hits, the CNG business might want to be ready for questions.


15 thoughts on “Checking in on CNG: Accidents Will Happen

  1. As a pressure vessel design engineer, these kind of accidents as of particular interest to me. However, the CNG tanks that are in service today have gone through rigorous testing and certification to get where they are now. The NGV2-2000 specification for Natural Gas Vehicles is not easy to meet. There are a lot of tests, including impact and penetration tests.
    My point is this: Gasoline is just as flammable as natural gas. Now, there are safety concerns because the natural gas is compressed, but so is the oxygen that firefighters use. Why are people so worried about filling up a tank with natural gas, when they fill up their car with gas weekly? The CNG tanks should, however, be removed from service if damaged. I am currently in the process of purchasing a bi-fuel vehicle for my personal use. This incident that happened in Carson, CA does not worry me. Sure I’ll inspect the tank that is in my car, and if I get rear-ended, no doubt, I’ll replace the tank. But we are around compressed gases all the time. We just need to respect the tanks.

    • How many parts are relieved from service if damaged? Do you know what it takes to determine damage like ultrasound, xrays, the list goes on.

      Why are people worried about CNG? Because it is not contained when it blows up. People can’t get away.

      What is the sense in this? You say we are around compressed gas all the time. But not to the tune of this kind of expansion. And to have a tank in a closed environment like a car? That is sheer terror to think of an accident in one’s car or a neiboring car.

  2. Thanks Jared. This is the kind of response I was hoping to get.

    You sound like an enthusiast, and a knowledgable one. But what about a guy like Mancuso? His main interest is in making money ferrying people to the airport. If, as a franchisee, his company says, “We run CNG vehicles,” he’s going to say, “Okay. Who fixes them?” If he’s referred to a mechanic, he’s going to trust his mechanic to do the right thing if there’s an accident, and has no way to verify independently if everything’s okay. Is there a protocol for dealing with rear-ended CNG vehicles in which the tank is always replaced?

    I have no idea what actually happened here, but it seems worth investigating further to ensure that the technology can reach its potential without posing unnecessary risks.

  3. My father was the victim of this terrible accident. I just returned from his funeral last night. The vehicle was looked at after the initial accident, and declared fine for road use. From what we can see, this accident did not contain fire, it appears to be a tank failure. We have no real details yet as the investigation is still ongoing. Thanks for bringing this topic to the public. As for photos, they can be found at

    Thanks again
    Bob Jr.

  4. Bob,

    I am so sorry for your loss and your family’s loss. The video at the link is heartbreaking.

    I’ll keep searching to find out whether investigators ever make a finding. If you get the news and are inclined to share it, please feel free to post it here, or to write me an e-mail at

    Thank you so much for writing. Again, my condolences.


  5. one month has gone by and not a tear has stopped
    my loving husband Robert lost his life filling his cng van. Still no answers!!!!!!!!!!!!!!!!why!!!!!!!!!!!!!!!!!

  6. Dianne,

    I am so sorry for your loss. I know how you’re feeling. This is an awful time. The best thing you can do for yourself is to be with the people who knew him and cared about him. Through talking, reminscing, and hearing old and new stories about him and your lives together, you can feel his presence…but also begin to do the hard work of letting go. Don’t rush yourself through this grief. Trust that it will pass.

    Just so you know, I sent a note tonight to the Daily Breeze, asking if they planned a follow-up story on what the investigation found. I’ll let you know if anything happens.


  7. I don’t know what happened in Carson but I spoke with the technician who services the Carson CNG facility and he told me that the van was declared safe to use (are they bi-fuel?) BUT the tank was condemned and shut off. According to him, Mr. Mancuso was under the vehicle opening the valve to the tank when it exploded. Could someone else confirm this scenario?

  8. yes i can confirm that the vans are not bi-fuel,the tank was damaged shut off and he was opening it when it exploded,regardless the van was in an accident and was repaired at the body shop,the tank should have been replaced not just shut off.

  9. just the other day i filled up my gas tank, after pumping, i took out the gas hose then a big bang went off. Suddenly the natural gas was blasting out of my van. I switch the emergency shut off valve on and began to take a look at it to fix it. I was taking my time looking at the fuel receptor when suddenly i felt nauseated I was dizzy then realized that motherfuckin van still leaking pressure alittle. fuck these cng vehicles. and Its soo hard to find a station and when you do, not just sometime but most of the time that shit station doesn’t work. and if it do work, something is always wrong with the hose. FUCK CNG……r.i.p. Mr Mancuso. and god bless your families…

  10. Robert was my uncle.
    My dad (his brother) has now gone to school to inspect and correct problems with these systems. He doesn’t want this happening to someone else. The people who did wrong here know who they are and they need to think about their actions. Don’t let this happen again to another family. Safety needs to be first.

  11. this is a real eye opener for me , as I work for a major public transit company here in los angeles and all the vehicles I drive on a daily bases are CNG with about 8 large ten foot tanks on the roof. I would like to get some info on the fueling stations if possible, there seem to be underground tanks with three large shacks off too the side of the station with large radiators on the front with what appears to be a large burner on the roof, can anyone shed any light on what this could be. every one at work seems to be very tight lipped. Hmmmmm? and yes please safety first!

  12. i work for veolia in australia, we had a OH,S set up in our yard,but its fallen apart and we are waitting for something to happen …hope not. Sound like your husbands accident was cause by bad repairers,were they skilled in that kind of repairs? sorry for your lost.

  13. Pingback: Preventing Explosions

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