One passenger says it felt like dropping in an elevator.
About 30 passengers on the LAX-bound flight were injured Tuesday when the plane hit severe turbulence over Kansas, the Federal Aviation Administration said.
The United Airlines flight originated at Dulles International Airport near Washington, D.C. It landed safely at around 7:45 p.m. Tuesday at Denver International Airport, where it was met by medical crews, Denver Fire Department spokesman Eric Tade said.
One person suffered critical injuries.
"It was like the bottom fell out," passenger Deborah Atwood told NBCLA. "One gentleman flew out of his seat and hit the man next to me.
"It felt like I had gone down an elevator shaft, hit the bottom, and came back up. If you didn't have your seatbelt on, you got hurt."
Passengers said the seatbelt sign was on.
"There was drink all over the ceiling," said passenger Jony Malchi. "Luckily, I had my seatbelt on."
FAA spokesman Ian Gregor in Los Angeles said 26 passengers and four crew members were injured. He said one person was critically hurt, but he released no further details.
Officials said many of the injured were transported to hospitals with only moderate injuries. By late Tuesday, some had been released or were expected to be released.
Some passengers were placed on another flight to Los Angeles that arrived there just before midnight.
Flight 967 was flying over Kansas at an altitude of about 34,000 feet when it hit the heavy turbulence, said FAA spokesman Mike Fergus in Seattle. It was carrying 255 passengers and 10 crew members.
"It was bad," said passenger Michael Batts, of Los Angeles. "The lady next to me hit her head. She went up about five feet, hit her head, broke the light."
United Airlines spokeswoman Megan McCarthy said the crew decided to be safe and land the Boeing 777 in Denver to tend to the injured.