On Feb. 21, the NTSB was notified of an accident on I-75 near Lake City, Fla., in which a 15-passenger van overturned and ejected passengers following a tire tread separation. Investigating crashes following tire failures is nothing new to us. At the time of the Florida accident, a team of our investigators was still on the scene of another tire-related crash that had occurred less than a week earlier in Centerville, La.

In the Louisiana crash, an SUV experienced a tire tread separation, veered out of control across a grassy center median area and crossed directly into the path of a school bus carrying a high school baseball team. In these two crashes alone, six people died and 38 were injured.

These two accidents prompted us to begin a special investigation focused on tire safety.

Although the special investigation is still in its early stages, several investigative areas are being considered, including proper tire maintenance procedures, tire recall process, potential degradation of tires due to aging, vehicle handling and driver response following a tire disablement and technological and manufacturing innovations.

Additionally, investigators will be evaluating numerous data sources to determine the overall scope of the tire-related crash problem and will be completing an analysis of the involved tires to determine the reasons for the tread separations.

A tire can fail for many reasons while a vehicle is moving. These include operation of the tire in an underinflated or overinflated condition, overloading of the tire, insufficient tread or uneven wear, tire punctures, manufacturing defects, and degradation of the tire due to age and operating environment.

Although the Florida and Louisiana accidents were similar in that the drivers lost control of their vehicles immediately after a tread separated from their left rear tires, the conditions of the tires involved were markedly different. For example, one tire was more than 10 years old while the other was only two years old.

For more than a decade, the National Highway Traffic Safety Administration has been conducting research into what happens to tires as they age. Although it’s clear that tires degrade over time, there are still debates among manufacturers and safety advocates about their service life.

Unfortunately, apart from tread life, most drivers know very little about tire maintenance and safety. For example, how many consumers even know the brands of the tires they’re driving on, let alone how old they are?

The two-year-old tire that failed in the Florida accident was a BFGoodrich Commercial T/A A/S tire, which was subject to a recall campaign initiated in July 2012 for approximately 794,000 tires. The safety recall notice stated, “It is possible that any one of the tires being recalled may experience tread loss and rapid air loss resulting from tread belt separation. This condition may increase the risk of vehicle crash.”

To date, our investigators have not found evidence that the owner of the 15-passenger van, the First Baptist Church in New Port Richey, ever received notice of the recall.

As part of our investigation, we’ll be examining the tire recall process to identify the responsibilities of the regulator, the manufacturer, the tire sales facility, and the consumer to determine if safety improvements are warranted.

Without question, tires are among the most important components of a vehicle as they are the only points of contact between you and the ground. If a failure occurs at any of these points of contact, a tragedy could occur. Our special investigation will focus on preventing future tragedies and making safety recommendations where improvements can be made.