November 15, 2011 at 4:15 AM EST - Updated June 25 at 10:03 PM
PALM BEACH COUNTY, FL (WFLX) Federal investigators from the National Transportation Safety Board said they will be returning to the Loxahatchee National Wildlife Refuge to continue their investigation into a single-engine plane crash that killed two people on Sunday night.
"We are in the process right now of formulating a plan of that recovery. Hopefully it will begin tomorrow morning. As far as how long that will take, I estimate one to two days," said Dennis Diaz of the NTSB.
Investigators spent an hour-and-a-half at the wreckage Monday, doing an initial assessment and accounting for what he called the four corners of the plane: the two wing tips, the nose and the tail.
"We know at least the entire airplane made it to the accident scene," said Diaz.
But he says they're still days away from determining what caused the crash.
He says they'll look at data from radar, the weather, history of the plane and talk to at least one witness who saw it go down.
The investigation has moved slowly so far because of swampy terrain and the threat of alligators.
The site is only accessible by airboat.
"Each one is unique, whether it's a frozen lake in Maine or the Everglades, each poses their unique challenges," said Diaz.
The single-engine plane is registered to Air Orlando, a flight school in Central Florida, but it was not on a training mission.
Rather, a spokesman for Air Orlando says the pilot was on personal business and likely headed to North Palm Beach Airport.
There are no "black boxes" on board like on commercial planes.
But the NTSB says they're hoping that new technology, that preserves readings on some of the instruments even when power goes out, will come in useful here.
Much earlier Monday, relatives of the victims were at the site, but they didn't speak with the media.