ONTARIO, Calif. (AP) _ No one was injured when a Sacramento-bound Southwest Airlines jet lost one of its rear tires upon takeoff and was forced to make an emergency landing.

``Landing without one wheel, it was an exceptional landing,'' said passenger Sandy Sarber. ``The pilots received a standing ovation. Well, a sitting ovation.''

Southwest Flight 253 left the Burbank-Glendale-Pasadena Airport shortly before 2 p.m. with 127 passengers and five crew members when the left rear outside tire fell off.

``I actually saw the tire rolling down,'' witness Mark Hardyment said.

It was unclear when the pilots knew the tire was missing but they were able to land safely at 3:20 p.m. at Ontario Airport about 45 miles southeast of Burbank, Southwest spokeswoman Carol Pearson said.

In another incident Thursday, 15 people were injured when their United Airlines flight from Los Angeles encountered ``wake turbulence'' from another plane.

Shuttle Flight 2036 ran into the turbulence at about 2:20 p.m.

``Everybody went straight to the ceiling,'' passenger Ronald Kalio said. ``There was two stewardesses that spent the rest of the trip in the aisles. They were knocked out.''

The Boeing 737, with 107 passengers and a crew of five, continued to its destination at San Francisco International Airport and landed safely less than an hour later, a Federal Aviation Administration spokeswoman said.