though they were subject to recall. Could your car be hiding this dangerous secret? Here is ABC's chief investigative correspondent Brian Ross for our series "Nightline" investigates. Reporter: The... See More
though they were subject to recall. Could your car be hiding this dangerous secret? Here is ABC's chief investigative correspondent Brian Ross for our series "Nightline" investigates. Reporter: The tire industry doesn't like to talk about it. But it has made and distributed millions of tires over the last decade that could lead to serious accidents. And as these safety tests show -- even a skilled driver who knows he is going to lose a tire cannot keep control. What is your emergency? Yes, I just had a bad accident. It's bad. She's hurt bad. Reporter: Despite a series of recalls. Something far too many Americans have learned only after it was too late. Like this professional model in Atlanta. Badly injured when a recalled tire fell apart. The next thing I heard a loud pop. Basically -- it went so fast. It's a big blur. Reporter: A business executive in Alabama, Caroline thorn paralyze Ford life. I heard a popping sound. And then just the car started vibrating out of control. You will see us through. Reporter: Members of this Baptist church in Newport ridgy, Florida, two adults dead, eight others injured as they drove to a retreat. Good takes tragedies and uses them for his glory. Reporter: According to federal safety investigators several hundred people are killed every year in accidents in which tires are a factor. Tires puncture or underinflated or poorly maintained or in some cases tires that were actually under recall because of safety defects but remained in use by motorists who apparently never got the word of the danger. All of this due in large part to an archaic and badly flawed recall system. Neither the government nor the industry have done much to fix. It is a mess. It doesn't work. Reporter: A safety analyst consults for government investigators and lawyers whose sue tire companies. Here we have a highly engineered product that offers great value to the customer. And yet, in 2014, we have no system to discern whether or not the tires are part of a recall. Reporter: In fact, an ABC news undercover investigation conducted with ABC stations across the country found potentially dangerous recalled tires still being sold at some retail outlets as if they were perfectly safe. There is no way that shop can examine the tire at a glance and determine whether it is part of a recall. There is no database. Most system. It really is the invisible hazard. Reporter: That's what she discovered after her accident. I learned that the tire blew out. I'm saying the tire blew out. Those are brand new tires on that truck? . How would a tire blow out. Reporter: She had taken her Ford explorer to a local Wal-Mart to check on the tires one week before the accident. The mechanics failed to realize the spare they rotated into use had been recalled as dangerous years before. That's the one that failed. The jury found Wal-Mart responsible. You count on them to do -- To do their job. Reporter: As a result? As a result I'm in this wheelchair. Reporter: In the case of the Florida church group they were in a van heading north on I-75 when a left rear tire blew. The driver lost control. And the van flipped over. The tire that police say was at fault had been under safety recall for more than a year. But apparently neither church officials or mechanics at Sam's Club where the tire had been serviced were aware of the looming danger. We're going to try to find out what happened along the way, who was responsible. Reporter: The national transportation safety board says the church accident helped trigger a first of its kind special federal investigation of tire safety. And the recall system's effectiveness for consumers and retailers. There is supposed to be a process in place to make sure that they know. But in many cases they don't. Reporter: As we saw in our undercover investigation, in San Francisco, reporters at kgo-tv went to a costco store they bought these three tires recalled last year because of a potentially serious safety defect. We were able to buy three recalled tires. Didn't appear itch any one knew they had been raumd. Awe all both costco and said those tires should never have been sold saying they don't know how it happened. In Atlanta the a small tire outlet, Jim Strickland, was able to biff one of the Firestone tires recalled in the year 2000 after dozens of deaths. More than a decade later, the salesman told him the tire was perfectly fine. A good tire? Good tire. Not one of the recalls is it? No. The store's manager later said he did not know the tire could be dangerous. I've don't know anything about it. We sell the tires. I didn't know it was recalled. It bears the blame because it doesn't do enough to alert consumers to many such tef recalls. In testimony for one lawsuit. An official company hired to handle recall reminder notices that some of them famed to be delivered because the notices were sent third-class male not first-class to save money on postage. Economics drive safety some times. Reporter: Firestone says recall efforts go well beyond what is required by the law. Industry says safety its its highest priority. We don't want recalled tires sold. Yet they are. Yet they are. Reporter: Dan salinski, Washington representative for the industry trade group displayed a lack of knowledge about the extent of the recall problem when heap sat down with us. How many tires hatch been recalled because of defects over the last decade. I don't know what that number is? Approximately. I don't know. I wouldn't ballpark a number. Reporter: You represent the tire industry you don't know the number. We represent companies that manufacture tires in the U.S. Reporter: You don't know the number. I don't know the number. Reporter: Took us 15 minutes to add up all the recalls going back to beginning of 2004 until this week. The total number of tires recalled for safety defects. More than of my million. For those five million plus how effective have the recalls been. How many get off the road. I don't have a percentage of that. You have no idea. I don't. We got an answer from the ntsb official investigating tire safety. To the best of my knowledge it is 20% or lower. Actually recalled. Actually physically recovered and sent to the manufacturer and looked at. Reporter: That means 80% or more of the recalled tires are never sent back to the manufacturer. Some may have been discarded by their owners. But doing the math, there appear to beep more than 4 million potentially dangerous tires that are unaccounted for. Is this recall system broke do you think? I think the recall system does need improvement. Certainly the notification does need improvement. Every tire has an alpha-numeric identification number. As Sean cane showed us there is no government website that allows consumers to enter the number and check on recalls. When you look at it, it is a complete disaster, confusing. You know what you are looking for. For the average person looking at the website. How difficult is that? For the average person. I don't think it's viable, feesable in any way shape or form. Of the nine ABC stations that went looking for recalled tires. Seven said the stores seemed to be doing a good job. They found no recalls for sale. As for the other two. Cane says given the mess of the recall system it really is no surprise that our ABC news undercover teams or any one could end up with potentially dangerous recalled tires. They're doing an inspection on tires. Rotate them. They can't tell us if they're recalled? That's stunning. Reporter: And devastating. For the congregation at first Baptist church in new portritchie, and Caroline thorn and Christian rose because of a tire recalled when she was a teenager, but still on the road. 14 years and it's still going on. That's scary. That's really scary. For "Nightline," Brian Ross, ABC news, New York.
This transcript has been automatically generated and may not be 100% accurate.