A Frontier Airlines pilot slammed on the brakes to avoid a collision at Los Angeles International Airport, and the Federal Aviation Administration is investigating the close call, according to an FAA-flagged account of the incident reported by the Associated Press.

The episode happened on a taxiway while the plane was moving slowly, not during a landing like a separate crash that occurred last month at New York’s LaGuardia Airport. The FAA said the near-miss involved vehicles that crossed in front of the aircraft on a service road, with the agency putting the time at about 11:25 p.m. Wednesday. The FAA said no one was hurt.

In radio audio posted by ATC.com, the Frontier pilot told the tower that the situation was extremely close and required immediate action to avoid hitting the trucks. The pilot said, “It was real close. The closest I have ever seen,” adding that he had to slam on the brakes. The Associated Press report characterized the pilot as having used an expletive while alerting the tower.

Frontier Airlines said it “thank[s] our crew for their vigilance and professionalism,” in a statement carried in the report. The airline did not provide further details beyond its message about the crew’s response, according to the account.

The FAA investigation is being prompted by how the incident unfolded around the moving aircraft and ground vehicles. The report said the close call appears to have taken place in an area of the airport where planes communicate with air traffic controllers about their movements, while the vehicles on the service road were instead supposed to yield to aircraft.

The Associated Press report also set the LAX incident alongside the March 22 crash at LaGuardia. It said an Air Canada jet carrying 76 people collided with a fire truck while landing, killing both pilots and injuring dozens of people. In that crash, the report said an air traffic controller cleared the fire truck to cross the runway less than 20 seconds beforehand, then called for the truck to stop moments before the impact.

The AP account said airport officials did not respond immediately to questions about what happened at LAX and what procedures are in place to prevent collisions. The story described that ground-vehicle rules are intended to keep vehicles from entering aircraft paths, even when planes are traveling at relatively low speeds—about 15 mph (24 kph), according to the report’s description.

Steve Arroyo, an aviation safety expert and longtime United Airlines pilot, said these incidents happen frequently on taxiways around the country but often draw no public attention when the collision is avoided. Arroyo said the recent events point to a need for closer scrutiny, adding: “Multiple incidents, accidents happening, just in March alone, I think it’s time to put some serious eyes on what’s going on on the ramp.”