BROWARD COUNTY, Fla. -- Investigators have found the bodies of all four people who were believed to be on two planes that crashed in the Everglades on Saturday.

A U.S. Coast Guard search and rescue helicopter spotted three areas of debris about 2.7 miles southwest of Holiday Park at 7:55 a.m. Sunday.

Related Content: Slideshow

On Monday morning, investigators from the National Transportation Safety Board and the Broward Sheriff's Office used airboats to search the crash site for victims and clues into what caused the crash.

The NTSB said investigators found all four bodies in the two cockpits on Monday morning. The Broward Sheriff's Office said Bryan Sax of Aspen, Colo., and Andrew Rossignol of Stuart were aboard the twin-engine Piper PA-44 Seminole involved in the crash. Stuart Brown of Pembroke Pines and Edson Jefferson of Miramar were aboard a single-engine Cessna 172.

BSO has confirmed that the bodies of Brown, Sax and Jefferson were found. They have not released the name of the fourth person whose body was found, pending the notification of next of kin.

It’s believed the two aircraft took off from North Perry and Fort Lauderdale/Hollywood International airports late Saturday afternoon. Brown was piloting the Cessna, while Sax was piloting the Piper, officials said. Both planes headed for the practice airspace over the Everglades, and they crashed midair, officials said.

At some point, the FAA was notified that the planes, operating under Visual Flight Rules (VFR), were overdue from training flights. The planes were not flying under the guidance of ATC radar. The pilots were visually scanning the skies for other planes, a common practice in the training area, Local 10's Roger Lohse reported.

The NTSB said an emergency locator transmitter sounded, alerting authorities to the crash, and a radar indicated that the planes struck each other.

The FAA told Local 10 it appeared both were participating in training exercises when they collided midair.

The information investigators find, paired with the fuselage a salvage crew plans to bring back to land, will give investigators a clearer picture of what the four people faced before the crash.

"Once the aircraft is out, we'll start laying it out and try to find the order that the aircraft collided. We'll use that with radar data to find out what happened at the time," said Eric Alleyne of the NTSB.

Finding answers won't be easy.

"It's a dense marsh. It's the Everglades," Alleyne said.

Investigators expect that the recovery phase of their work will last at least two days.

Brown was the assistant chief flight instructor at the Pelican Flight Training Center. Colleagues said Brown was an accomplished and safety-conscious pilot who had been working at the academy for about two years. He started there as a student and worked his way up through the ranks.

Friends said that pilots typically get on a designated radio frequency when they approach the training area over the Everglades in order to let other pilots know they are in the area. They said Brown was a stickler for doing this because he knew of the risk for midair collisions in the high-traffic area.

"It could happen to anyone, a midair collision, so we need to wait and see what the reason was," said Lucas Soori, a flight instructor at Pelican.

Jefferson, who was also a pilot, was on his final training flight with Brown before he took the test for his IFR certification, which means he would be allowed to fly in bad or foggy weather using only the instruments for navigation. Jefferson was supposed to take the test on Monday.

Sax was a father of three. Family members confirmed to Local 10 that Rossignol was also in the Piper. They said Rossignol recently moved to South Florida from Maine in order to earn flight time as he worked toward becoming a commercial pilot.

Investigators plan to continue Tuesday to recover parts of the airplanes.