Explore More Aviation Case Studies & Examples
On March 22, 2026, Air Canada Express Flight 8646 collided with a fire truck on Runway 4 at LaGuardia Airport. The aircraft, a CRJ-900 operated by Jazz Aviation, was landing after a flight from Montreal. At nearly the same time, a fire truck responding to a declared emergency on United Flight 2384 requested permission to cross the runway at Taxiway D and was cleared to do so.
In the minutes leading up to the collision, controllers were already managing an active situation. United 2384 had aborted takeoff, reported an odor onboard, and ultimately declared an emergency as crew and passengers began experiencing discomfort. The fire truck positioned near Runway 4 was there to respond to that event.
What Happened
At 11:35 PM, Air Canada Flight 8646 was cleared to land. About a minute later, the fire truck requested and received permission to cross Runway 4 at Taxiway D. Roughly 25 seconds before the collision, the aircraft was on final approach. Around 10 seconds before impact, the controller issued an urgent command: “Stop, stop, stop.” The aircraft touched down seconds later. The fire truck remained on the runway. The collision occurred at approximately 11:38 PM.
The impact was severe. Both pilots were killed, and 41 others were hospitalized. The aircraft and fire truck were destroyed, and operations at LaGuardia were disrupted with a ground stop.
Why It Happened
As NTSB Chair Jennifer Homendy said in the days following the incident, “When something goes wrong, it means many, many things went wrong.” I couldn’t have said it better myself.
The aircraft and fire truck ended up on the same runway at the same time, but multiple factors had to line up to arrive at that outcome. The fire truck had to approach the runway even though the safety lights were on. Clearance had to be given with some expectation about how quickly that truck would move. And by the time the situation was recognized, there just wasn’t enough time to stop it.
This is where Cause Mapping® root cause analysis (RCA) becomes useful—not to assign a single cause, but to show how multiple conditions combine to produce an outcome.
In the video below, I walk through a Cause Map™ diagram built from the known facts to show how these conditions connect. I also include one of my hot takes on a factor that may have had an outsized impact on how this sequence developed.
What’s Next
The NTSB investigation is ongoing, and additional evidence will continue to shape the explanation. I’ll be watching closely for what the data shows around visibility from the fire truck, the role of runway safety lights, and whether the stop command was received and understood. I’m also interested in how timing played into the sequence, specifically with regard to what the controller expected when granting clearance and how that compares to what actually happened.
As more information becomes available, parts of this analysis may change. That’s expected. The goal at this stage is to build the clearest explanation possible from the known facts and refine it as new evidence comes in. To get updates on this investigation and other new case studies, consider subscribing to our weekly newsletter.
