Ambulances, fire trucks and police vehicles gathered at the edge of the airfield where smoke billowed from the woods.
Wounded passengers lay on tarps, waiting to be transported to hospitals.
Required every three years by the Federal Aviation Administration, the emergency response drill brought together 150 people from 19 volunteer fire departments, six volunteer ambulance corps, the Suffolk County police, federal agencies and airport first responders.
The scenario: While taking off, a Boeing 737 with 98 people on board slid off the runway into the trees, said Teresa Rizzuto, the airport's aviation commissioner.
"We never want an incident to occur, but if it does, we need to be prepared," said Catherine Green, an airport spokeswoman.
Instead of a plane, firefighters worked on an old tractor trailer. Trees were down on top of it and smoke bombs clouded the scene. The "wounded" rambled around, wearing colored tags denoting their injuries.
Inside, a half-dozen 175-pound mannequin "passengers" were strapped in their seats.
Melville residents Debbie Archer, a volunteer EMS with the Melville Fire Department, and her daughter Beth, a junior firefighter, were among those playing the wounded. Mom had fractures of the tibia and fibula (bones in the leg); daughter suffered burns.
The exercise gave them a new way of looking at an emergency.
"I think it's amazing," Debbie Archer said. "It's a great experience for all of the departments to work together and to see it from the perspective of the victim."
Twenty-six of the "injured" were taken to three hospitals -- Southside Hospital in Bay Shore, Brookhaven Memorial Hospital Medical Center in Patchogue and St. Catherine of Siena Medical Center in Smithtown.
The idea was to test hospital capacity in dealing with multiple injuries, said Bob Delagi, director of Suffolk County's Emergency Medical Services Division.
While rescue operations were under way, airport officials gathered in a command room, watching the scene by video feed from four live cameras.
Everyone had a job: to do press interviews, handle family, account for spending, coordinate emergency response and other tasks.
Whether the airport shuts down, even briefly, depends on the severity of an incident, said Rizzuto, who added that the drill seemed to go smoothly.
Press was kept at a staging location and not allowed onto the runway or field. "We just need to protect the passengers," Rizzuto said.