A SkyWest Airlines flight, traveling from Chicago to Connecticut, had to make an emergency landing at Buffalo Niagara International Airport on Wednesday, after three people lost consciousness on the flight. All 75 passengers, including two children, on board the plane were evacuated upon landing and released after being checked for medical problems.

SkyWest Flight 5622 descended rapidly from an altitude of over 28,000 feet to 10,000 feet in a few minutes, a local affiliate of Fox News reported. However, an investigation into the incident later found that there was no problem in cabin pressure and that the oxygen masks did not release, the cabin’s crew said, according to the Associated Press. 

“There were no reports before the unconscious passenger prior to the initiated descent, but I can’t speak to what may have been the specific cause of their feeling ill,” Marissa Snow, SkyWest’s spokeswoman, said, according to the AP, adding that the maintenance personnel also did not find any faults with the pressurization.

The Federal Aviation Administration had initially said that the crew "reported a pressurization problem and declared an emergency" just before they landed in Buffalo. But this was later found to be incorrect, the Sydney Morning Herald reported.

"We were all told to just keep breathing and as we were told to keep breathing, we suddenly went into a nose dive," Vanessa Bergmann, a passenger on the plane, said, according to NBC News, adding: "And that rapid descent was incredibly scary. It really felt that we were diving down uncontrollably."

However, a report from Fox CT, said that the claims from the airlines contradicted the experiences of the passengers. Mary Cunningham, an emergency room nurse from Niantic, Connecticut, who helped the passengers, said many passengers on the plane’s middle section, including herself, felt light-headed and ill.

“I saw at least two and then other people experiencing symptoms that weren’t as severe but I can tell you I was told the first person was passed out,” Cunningham said, according to Fox CT, adding: “She was very lethargic and didn’t look good and the second patient I saw was passed out.” 

Another passenger, Frank Angelo from Simsbury, Connecticut, told Fox CT: “The captain came on the PA system and he announced that we were going to descend really quickly,” adding: “Sure enough, within seconds, that aircraft felt like it nose-dived. Engines full throttle, the air frame shaking, and we descended really quickly.”

The airline is still investigating the incident.