July 21, 2010 -- Passengers on a cross-country flight were sitting calmly in a United Airlines aircraft high above the American Midwest when suddenly the plane lurched into a free-fall sending people literally flying into the cabin ceiling, passengers recounted today.
"For those couple of seconds I just saw people fly up in front of me and actually the lady sitting beside me, she flew up too. She hit the ceiling and landed on my lap," passenger Bryan Liu told "Good Morning America" today. "So at that moment I just tried to grab her and hold on to her as long as I can."
Fellow passenger Kaoma Bechaz said that shortly after being stunned by the sudden drop, many passengers reacted.
"I sort of panicked... I did hear a lot of screaming," Bechaz said. "I just looked at the lady next to me and she grabbed my hand and said, 'It's OK. We're OK.' Everyone pretty much calmed down once they felt we were moving OK again."
Luckily for the 255 passengers and 10 crew members aboard United Airlines flight 967 Tuesday night, the plane recovered from the sudden drop, but not before more than two dozen passengers were injured. The flight from Washington, D.C., originally intended for Los Angeles, was diverted to Denver where several passengers and crew were taken by ambulance to the hospital. At least one person was critically injured, The Associated Press reported.
The seatbelt sign was on when the plane struck the turbulence over the American Midwest, a United Airlines official told ABC News, but not all passengers were strapped in.
"I saw at least two people hit the ceiling," passenger Alexander Walan said Tuesday. "A girl in front of me -- two rows -- I saw her hit the ceiling and slammed back down. Luckily I had my seatbelt on."
One woman was tossed with such force that her head cracked the ceiling of the cabin.
Afterwards, Liu said passengers settled down as flight attendants walked the aisles to assess any injuries and damage.
Injury-Causing Turbulence Not Uncommon Problem
United Airlines found flights on to Los Angeles for the uninjured passengers late Tuesday night.
The plane suffered no obvious external signs of damage from the turbulence, but will be thoroughly inspected, officials said Tuesday.
It's the third instance of injury-causing turbulence for United Airlines this year. In February, 20 people were hurt on a flight from Washington to Tokyo and on May 10 more passengers suffered injuries including broken bones in rough air over the Atlantic Ocean.
"This is depressingly familiar," ABC News aviation consultant John Nance told "GMA" today. "About 60 people a year get hurt by this. We've all hear the prohibitions about sitting down in your seat without putting your seatbelt on, but unfortunately there's always a number of people in the cabin who don't have their seatbelts on when something like this hits without warning.
"This is a real danger if you're not buckled in," he said.
According to a Federal Aviation Administration official, in the past 30 years only four serious injuries have occured due to turbulence when people are properly strapped in.
"These days, most turbulence injuries are to flight attendants who are moving about the cabin," spokesman Ian Gregor told ABC News. "The bottom line is that if a passenger is seated and properly secured, there is almost no chance of being injured due to turbulence."
ABC News' Matt Hosford and Lisa Stark contributed to this report.