The systems in place at New York’s LaGuardia Airport to prevent ground collisions failed to keep an Air Canada jet from smashing into a fire truck that had just pulled out on the runway as the plane was landing.

The National Transportation Safety Board will determine what went wrong before Sunday’s crash that killed both pilots and injured dozens of others. One of the two air traffic controllers on duty that night cleared the fire truck to cross the runway just 12 seconds before the plane carrying 76 people touched down. His frantic calls moments later for the truck to stop didn’t prevent the collision.

There will almost certainly be multiple factors that contributed to the crash because the aviation system has many layers of precautions in place to help reduce the risks of such an event happening. Investigators are just beginning to interview everyone involved, examine the wreckage and test everything that could have played a role. The mangled plane was being moved to a secure hangar Wednesday for further examination.

Surface tracking systems have prevented numerous crashes

LaGuardia is one of 35 major airports nationwide that have Airport Surface Detection Systems known as ASDE-X that combine radar data with information from transponders inside planes and ground vehicles along with other data to create a display in the tower showing controllers where every plane and vehicle is. The system will also sound an alarm in the tower when it anticipates a potential collision.

Just last fall the NTSB credited that warning system with preventing a private jet from running into a Southwest Airlines plane on a runway in San Diego in August 2023. That alarm got the attention of the controllers in time to keep the planes from colliding even though they came within 100 feet of each other.

The system also was credited with keeping a JetBlue plane from hitting another plane crossing a runway in Boston in 2023, and it has been praised in numerous other NTSB reports over the decades since it was created in the late 1990s. A predecessor system dates back to the 1980s.

Only the busiest U.S. airports have received the costly ASDE system, but the Federal Aviation Administration is in the process of installing a lower-cost version at 200 other airports over the next few years. That system is already in place at 54 airports and is one of a number of measures the FAA has taken as part of its goal to eliminate runway incursions and collisions.

The number of emergency vehicles parked on the taxiway Sunday — they were en route to help a United Airlines plane that had reported a strange odor making flight attendants feel ill — made it difficult for the system to predict a potential collision. Rick Castaldo, who helped design and install the ASDE systems during his career at FAA before he retired, said the system is better at predicting potential collisions when vehicles or planes are moving. Its computer can’t predict what a stopped vehicle is going to do.