Authorities still are investigating why a twin-engine plane crashed Thursday into a ditch at Hilton Head Airport.

The 1965 Cessna 310J ran off the runway at about 3:15 p.m. as it was landing to the southwest. It ended up in a ditch full of water beside the taxiway at the far end of the runway.

Christopher Daniel Criss of Mims, Fla., had taken off from an airport near his home with a passenger and was headed to Hilton Head Island. Neither he nor his passenger was injured.

Circumstances regarding how and why the plane left the runway still were unknown Monday, according to Warren Woodberry, spokesman for the Federal Aviation Administration.

"It's being investigated by the FAA," he said.

Criss, who was issued his pilot's license in September, said he has been advised by the FAA and the National Transportation Safety Board not to discuss the crash publicly until the agency has issued its report. The plane is owned by his father, Daniel Criss.

The wreck closed the airport for about an hour Thursday afternoon until authorities gave the OK to have the plane removed from the ditch.

The last major crash at the airport occurred in August 2003 when a Piper Malibu with a missing fuel cap crashed into the woods while trying to make an emergency landing, according to the NTSB. The pilot and his wife were killed.