Two planes collided while trying to land at an airport near San Jose, California, on Thursday.
Authorities said three people died in the crash, one person in the Cessna 152 and the two people in the Cessna 340.
"We are absolutely saddened to hear about the tragic incident that took the lives of several people," the City of Watsonville said in a post on Twitter.
People nearby rushed outside to see what happened after they heard an explosion.
"Massive plumes of white and black smoke and fire on the runway," said Mitch Valdez, who works near the Watsonville Municipal Airport.
No injuries were reported on the ground.
The NTSB and FAA are investigating why the planes collided.