Firefighters, police officers, and other emergency personnel quickly descended on the airport as flames engulfed the aircraft.
Roughly 30 members of the San Diego Fire-Rescue Department were dispatched to deal with the burning wreckage.
The department alerted the public to the unfolding emergency in a post on X.
“Approximately 30 SDFD personnel are on scene of a small plane on fire on the runway at the Montgomery-Gibbs Executive Airport. The airport will be temporarily closed during emergency operations,” the San Diego Fire-Rescue posted on X.
Authorities subsequently announced that two people had died in the crash.
Officials had not immediately identified the victims.
It was also unclear what happened in the moments before the aircraft went down or whether the pilot had reported experiencing trouble before the crash.
Witnesses working in the vicinity described seeing the aircraft burning as emergency vehicles poured into the airport.
The fire and resulting emergency response forced officials to temporarily halt airport operations while crews worked around the wreckage.
Investigators are now tasked with piecing together exactly what happened.
Among the key questions will be the aircraft’s condition, its flight path, the actions of the pilot, weather conditions, and whether any mechanical problem contributed to the disaster.
No official cause had been announced in the immediate aftermath.
The tragedy is especially striking because it follows another fatal California plane crash only two days earlier.
That separate disaster occurred near Sierra Sky Park Airport in Fresno and wiped out a family of four.
Flight instructor Danna Eady, 41, was killed along with her husband, Craig Eady, 44, and their two young sons, Pavel, 10, and Remus, 13.
Their single-engine aircraft crashed Saturday near the Fresno airport.
First responders arriving at that scene encountered a devastating wreck.
Debris from the aircraft was scattered around an area near a bluff overlooking the river, while fire from the crash reportedly spread into vegetation on a nearby hillside.
All four family members were killed.
Then, just two days later, California first responders found themselves confronting another burning aircraft — this time hundreds of miles south in San Diego.
The two crashes are not known to be connected, but their close timing has resulted in an especially grim stretch for aviation in the state.
Monday’s accident also brought an abrupt shutdown to Montgomery-Gibbs Executive Airport while emergency personnel secured the runway and dealt with the aftermath.
The airport is a significant general aviation facility in San Diego and handles a variety of private and business aircraft operations.
For those who witnessed Monday’s crash, however, routine airport activity was suddenly replaced by flames, emergency vehicles, and a massive first-responder presence.
Authorities have so far released few details about the aircraft itself or its occupants.
That leaves several major unanswered questions, including where the plane had departed from, where it was headed, and what caused the flight to end in catastrophe on the runway.
Investigators will likely examine available flight information, aircraft maintenance records, communications, surveillance footage, and physical evidence recovered from the wreckage as they attempt to establish a timeline.
For now, officials have confirmed the most devastating fact: two people lost their lives.
Their deaths bring another round of tragedy to California’s aviation community only days after the Fresno crash claimed an entire family.
What should have been an ordinary Monday evening at Montgomery-Gibbs Executive Airport instead became the scene of a fatal inferno.
And until investigators determine exactly what happened, the question hanging over the San Diego runway remains the same one facing investigators in Fresno: what caused another small aircraft flight in California to end in disaster?
