None of the four people on board a twin-prop Cessna 340 that crashed in the Great Dismal Swamp on Thursday survived, Virginia State Police said.

After a search that lasted 24 hours and a further effort to reach the remote area of the crash, which was located by helicopter, search crews confirmed the 61-year-old pilot, Theodore Bradshaw, his wife, Mary Anne Bradshaw, 48, Charles Rodd, 64, and Diane Rodd, 58, all of Florida, were dead.

Bradshaw had more than 30 years of flight experience, according to the state police.

The search began Thursday when state police were notified the plane, which had left Fort Lauderdale, Fla., about 7:43 a.m. Thursday, had not reached the Hampton Roads Executive Airport as planned. The Norfolk air traffic control tower lost radar contact with the plane shortly after noon Thursday.

A privately owned helicopter assisting with the search effort spotted the plane shortly after 4 p.m. Friday and provided its coordinates to ground crews, who reached the site more than two hours later.

The crash is in an “extremely remote” section of the swamp on the Virginia side. On Saturday, Dismal Swamp Canal Park officials will begin using a bulldozer to clear a path for four-wheel drive vehicles to reach the site.

“We want to express our sincere appreciation to Hampton Roads Helicopters for their critical assistance with this search mission,” said Lt. Curtis Hardison, Virginia State Police Chesapeake Division. “They not only supplied us with the necessary aerial support we needed to expedite this search operation, but provided two hours of flight time free of charge. Their generosity also helped bring closure to the families of those who lost their lives in this tragic crash.”

The cause of the crash remains under investigation.