The people on board experienced a little of everything. They saw smoke, flames, heard noises and many even took pictures of the damaged plane.
According to the FAA, what left such a massive dent in the 757's right engine was a bird or possibly an eagle. It flew into the engine five to seven minutes after take-off.
"There was a guy in there and he was pulling feathers out of the top of the engine there," said Mike Ficco, a passenger.
"We just cleared the edge of the runway and there was a bird that hit the top of the engine, part of the bird flew over the top of the engine, part to the bird was sucked into the engine and the engine made a grinding sound," said Gary Little, a passenger.
But the noises weren't the only things making passengers hold on tight to their arm rests.
"The plane kind of shook a little bit and we started smelling a weird smell in the plane and then I looked out the window to the right and saw a flame shoot out the back of the engine and we were pretty scared," said Nav Khalsa, a passenger.
"There were a few more flames shooting out of the engine and the pilot just said, 'Prepare for landing,'" said Rebecca Lynn, a passenger.
While the plane was at around 2,000 feet, the pilot decided to make a mid-air U-turn, and fly back to Denver as a pre-caution. And that's also when he told passengers about the possible bird strike.
"One of the first thoughts was just that, 'Oh my God, I hope what happened in New York doesn't happen," said Khalsa.
Many on board immediately thought of the January 15th emergency landing of a US Airways flight on the Hudson River. Birds flew into both engines of the plane that time. Pilot and Danville resident, Sully Sullenberger brought the plane down safely. But Tuesday, it wasn't a flock of birds, just one, that caused Lynn Gayno to spend the night in San Francisco. She missed her connection to Honolulu.
"You'd think they would've developed something to keep the birds out of the engines by now!" said Gayno.
Both SFO and San Jose International have staff to monitor the bird population, but at Oakland's airport they spend a $250,000 on two full-time bird monitors from the USDA. Still, according to the FAA, bird strikes are fairly common. There have been more than 100,000 since 1990.
