CHICAGO (CBS) — It was a flight they’ll never forget. Terrified passengers on a flight from Chicago to Connecticut took 28,000-foot nosedive on Wednesday, as their plane made an emergency landing after three people on the plane passed out.

SkyWest Flight 5622, operating as United Express, took off from O’Hare International airport at 9:20 a.m. Wednesday, bound for Hartford, Connecticut, but was diverted to Buffalo, New York, when a passenger lost consciousness. Although initial reports indicated only one passenger passed out, the airline later confirmed three passengers lost consciousness.

To make its emergency landing, the plane made a dramatic drop. In just three minutes, the jet carrying 84 passengers and crew descended from 38,000 feet to 10,000 feet.

“The scariest thing was really just the nosedive that happened. I mean, it was very obvious that we were descending as rapidly as we could at that point,” passenger Vanessa Bergmann said. “I can’t even remember if I was flying forward, or being pushed back.”

The plane landed safely at Buffalo Niagara International Airport at about 11:40 a.m., and passengers were evaluated by medical teams on the ground, and were released. No one was taken to a hospital.

SkyWest officials said the pilot feared passengers had lost consciousness due to pressurization problems, but that turned out not to be the case.

The standard response to a loss of cabin pressure is to descend to a lower altitude, to find more oxygen as quickly as possible.

“That is far greater than the rate of descent for this plane. Obviously the plane could withstand it. It’s beyond the envelope of what you need to do, so you know that these pilots knew they were in a very grave and very serious situation,” said aviation attorney Mary Schiavo.

It was unclear why the passengers lost consciousness, but the airline said it is investigating.