LEHI -- A small plane crashed Wednesday afternoon near Thanksgiving Point in Lehi.
The pilot, 52-year-old Mark Thorn of Sandy, was critically injured, but aviation experts said his actions may have prevented others on the busy freeway from getting hurt.
Exactly what happened is still not known, but Thorn gave a distress call just before he put the plane down between Interstate 15 and the southbound off ramp to the Alpine-Highland exit.
"As he came out of the south, it looked like he veered off just enough to miss the oncoming traffic heading southbound. And he was listing a little bit, probably to the west, and then I seen him disappear behind the freeway," said witness Mike Frandsen.
The first 911 call came in at 2 p.m. Thorn was treated inside an ambulance until he could be flown by LifeFlight to Intermountain Medical Center. He is in extremely critical condition, with head injuries.
Thorn was the only person on board and was traveling from St. George to Salt Lake. A pilot in the air at the same time told KSL News he heard a mayday call on the aviation radio and the pilot describing a fuel problem.
Because planes are often told to follow the freeway by air traffic control, I-15 may have been Thorn's only option.
"You are limited by the options, and sometimes the options are not all good options," said Bill Ogilvie, professor of aviation at Westminster College.
Ogilvie said he and his colleagues teach their students to be ready for an in-flight emergency by being prepared for anything, knowing decisions must be made quickly.
"It's playing a ‘what if' game, and you have to play the game over and over and over and over and over again, so when that adrenaline starts rushing you are doing what you've practiced," Ogilvie said.
The crash caused freeway traffic to come to a halt for more than an hour, and the Alpine off-ramp was closed for some time.
The Utah Highway Patrol, the FAA and the NTSB will all work to find out what happened in the air. The crash site is being guarded by the highway patrol until the investigation here is finished and the plane can be moved.