Smoke was reported in the cabin and cockpit of United Flight 1296 about an hour into the flight. The plane was heading to Kona, Hawaii with about 150 people on board.
Oxygen masks were deployed and passengers were ordered to put on their life jackets, and practice the crash maneuver position.
"We practiced the crash maneuver, where you you have to hold, it was very scary," said passenger Debra Elder.
Eyewitness News has learned resources for LAX emergency landing were called off shortly after 11 a.m. because the plane was going to be diverted, possibly on San Nicolas in the Channel Islands, according to passengers.
"They talked about having to land on a small island, maybe an airstrip that can't handle a 757," said passenger Ken Mitchell.
The plan was eventually scrapped. Military fighter jets escorted the Boeing 757 and LAFD was deployed for LAX at 11:18 a.m.
A command post was also set up on Imperial Highway at Main Street, located west of Sepulveda Boulevard.
The plane landed without incident at 11:38 a.m., the FAA said. Fire Department engines and ambulances sent to the airport as a precaution were released after the safe landing.
There were no reports of injuries, but many passengers were left frightened following the incident.
"You look out the window, and there's a bunch of water so you're thinking 'alright, this is probably not going to end well,' said passenger Gail Baumkirchner.
United said passengers were being transferred to other flights. The aircraft was set to undergo a thorough inspection by maintenance crews.
CNS and The Associated Press contributed to this report.