Transcript for BMW mystery fires: Parked cars have burst into flames
Tonight a growing and dangerous mystery. S dos of BMW owners claiming their vehicles suddenly caught fire while parked and turned off for hours. What could be the cause? ABC's Brian Ross teams up with our stations across the country to investigate. Reporter: The owner of this BMW told us he still can't believe what happened to his car. Oh my goodness! Reporter: After he went inside to his office for the day. I had parked it for maybe, say, five minutes. It was completely turned off. Reporter: But then over the next nine minutes and 15 seconds, as this home video shows, a white wisp of smoke coming out of the front hood followed by heavy smoke, then flames. Yeah, it's on fire. I'm so scared. Reporter: Enveloping the car. Oh, wow. Reporter: As firefighters arrive. They struggle to put it out. In the end, a total loss. And a very big question of why for the owner for BMW. I definitely feel there's something that should be investigated as to why this is occurring. My car is on fire. Jimmy: It is a question being asked byes dos of BMW owners around the country. I hadn't driven all day. I'm standing there in shock, shaking. Just like, oh my god, I can't believe this. How did this happen? What type of vehicle is on fire? Reporter: And by fire departments too. A BMW, black BMW. Reporter: All involving BMWs described as safely parked and turned off. That's not supposed to happen. When a car is off and it catches fire, you've obviously got a problem. Reporter: BMW says it has found no problem or defect for BMW owners to be worried about. But an investigation by ABC news -- Fire was coming out from under here, going up the side of the car. Reporter: And our abc-owned stations around the country -- They want to know why their high-end vehicles, many of them parked, suddenly caught on fire. Reporter: Discovered dozens of such mysterious fires over the last five years. Including this BMW just last month in southern California. Had parked the car, went inside, was doing what I needed to do. Woke up to -- a car on fire. Reporter: The owner's darth vader costume, which he uses for children charity, was spared. In suburban New York, firefighters were stunned when they learned how long this car had been parked before catching fire. It had been parked for three or four days. Which we thought was a little peculiar. What if that car had been in the garage? We would be having a different conversation right now. Reporter: But that is of great concern. House on fire, right next to the house -- Reporter: In gloucester, Massachusetts, earlier this year a fire in a brand-new BMW quickly spread to the house. Now the house is on fire. Reporter: The car had been parked for five hours and not moved, according to the deputy fire chief Steven ayello. That surprise you? Very surprising, the first one I had heard of in 32 years on the job. I think most people think once they turn the key of their igniti ignition, the vehicle is off and that's it, it can't accidentally catch on fire. In this case, that's what happened. Reporter: And what happened in Maryland outside Washington, D.C. Where the residents were lucky to get out in time. I think this was a five-alarm fire. The wife had an office in here. Well that got completely destroyed. Reporter: Bigg Maco says his wife parked their BMW x5 SUV in the garage. There is black smoke and snack, crackle, pop. Then flame. You cannot do a thing except watch. Reporter: Like others we talked with, Maco, a long-time BMW customer, said BMW gave him the cold shoulder after the fire. I feel like I'm just tossed aside. You know, it's just a number. Not even an apology. So -- that's the sad part. Reporter: BMW says it has nothing to apologize for. Its executives refused repeated requests from "Nightline" to appear in our report. But in a written statement BMW said, based on its investigation, it has seen no pattern related to quality or component failure. And it said these fires could be caused by outside factors, including poor maintenance or rodents' nests. We don't make sports cars -- Reporter: With almost 5 million BMWs on U.S. Roads, the company says such fire incidents are rare. Its brand is built on its high performance, precision German engineering. We only make one thing. The ultimate driving machine. Reporter: But this series of fires now may raise questions about BMW's reputation for excellence. According to lawyers who have been hearing from BMW owners. It's a pattern that BMW is uniquely qualified to remedy. But they have not? They have not, no. Reporter: Joseph Santoli says angry BMW owners like Oscar and Sarah day are telling him BMW is refusing to deal with the problem. I wish they'd do something -- do the right thing. That's all I'm hoping for. I have heard from owners that when they confront BMW about their incident, they're told that this is the first time that BMW has ever heard of it. Can that be true? I don't believe it can, no. So what's happening? I think some of it is an example of BMW burying their head in the sand. Reporter: Car fires and related recalls are not uncommon. But almost entirely for problems when cars are being driven. The number of those in which the car is actually off and sitting for a long time are very few -- Reporter: Auto safety expert SHAWN Cain says what's causing this series of fires in parked BMWs is a mystery that likely grows out of the fact that cars now are never really completely off. The answer, whatever it is, is going to be in here somewhere? The answer's going to be there, sure. Even when you tour turn the car off, it's not really off? The engine may be off. But all the electrical power systems that are going to do things like keep the high pressure fuel pump ready, the door lock sole noids powered, entertainment system, all these things are drawing from the battery, still drawing energy. Reporter: BMW has issued its own recalls over the years for fire-related issues. But in at least 43 of the cases we found, there were no such open recalls. Not for the 2008 BMW that led to this huge fire in Maryland. Not for this 2011 BMW 328 model. No recall for the 2016 BMW that caught fire three months ago in Massachusetts. This is a 2016 vehicle, a brand-new vehicle. Reporter: BMW told us it is now investigating this case. But deputy chief ayello says while he's had a lot of calls about the mysterious fire, he's not heard from BMW. You've heard from fire departments, car owners? Other fire departments, other car owners, other people of interest, fireinvestigators. All contacted you? Yes. But BMW did not contact you? No, BMW has not reached out to me. Reporter: For bill Maco in Maryland, after that huge fire, his insurance company is covering the cost of rebuilding, including a new garage. I'll park my vehicles in it but it will never be a BMW. So that won't happen, no. Not at all. Reporter: For "Nightline," Brian Ross, ABC news, New York.
This transcript has been automatically generated and may not be 100% accurate.