Passengers told ABC11 the pilot went on the loudspeaker and said plane was going down.
"We all thought we were descending to our deaths. My husband and I were clenching hands and saying 'I love you, you know, this is it.' And I think I was praying out loud and I'm sure a lot of other people were too," recalled passenger Phyllis Fann.
Southwest told ABC11 Flight 3426 was headed from Tampa to Raleigh when the crew of the Boeing 737 got a warning that there was a cabin pressure problem.
In a statement, the airline said: "As part of the procedure to resolve the issue, the Captain notified the cabin using the public address system that he was going down to a lower altitude just before an unplanned but controlled descent. The maintenance issue was resolved before the flight safely landed at Raleigh-Durham."
In an email to passengers, the airline said as the captain was communicating his plan with the flight attendants, he inadvertently activated the public address system in the cabin.
Southwest said the plane descended rapidly from 40,000 to 25,000 feet. Passengers told ABC11 it felt like the aircraft was in a nosedive.
"I thought I was going to die and that's what everyone on that plane thought. That we were all going to die, just by one word of the captain. I just think they could have handled it a little differently," passenger Shelley Wills said.
Kevin Emery was also on the flight. He's not happy with the letter of apology sent out by the company.
"I just think the overall response from Southwest as a corporation in that message was just absolutely poor," said passenger Kevin Emery.
Emery remembers what happened differently.
"When the pilot came on the PA system he specifically addressed the passengers and the crew at the same time," said Emery. "You could tell he was struggling, maybe putting on an oxygen mask, something kept hitting the mic. Then the last thing he said was 'We're going down.' I understand it was the heat of the moment, it's just one of those things you never want to hear on an airplane."
ABC11 also spoke to fellow passenger Toby Shelton by phone. He says he found the wording in the letter where they say they regret the "uneasy feelings felt before landing," to be a humorous understatement.
"The uneasy feeling made me laugh," said Shelton.
There were 96 passengers and a crew of five on board the jet. All made it to Raleigh safely.
Southwest said it was not technically an emergency landing, but any time you deviate from a flight plan, unplanned, a pilot will declare an emergency. Southwest said the pilot of Flight 3426 did exactly what he was supposed to do.
It's giving passengers a $200 voucher they can use for future travel.
Some say the voucher is a nice gesture while others say they would rather read a more truthful apology letter.
"That's just an insult to the passenger's intelligence," said Emery.