Passengers told ABC11 the pilot went on the loudspeaker and said plane was going down.
Now, experts are weighing in on what could have gone wrong.
The pilot on Southwest flight 3426 sprang into action Tuesday when his plane began losing cabin pressure. The aircraft made a dramatic descent from 40,000 feet to just 9,900 in about 10 minutes as it was heading to Raleigh.
"I fly a 737 also. My assumption is that one of his air conditioners which provides pressurization of the airplane was malfunctioning," said pilot Tal Holloway. "When that happens, the first thing that you do is, you have to descend to a lower altitude."
Holloway, who is a 30 year veteran, says pilots are then trained to put on their oxygen masks, but it's what happened next that had passengers panicked.
The pilot accidentally announced over the public address system "We're going down." It was a message meant for crew members.
"It's very easy to hit the wrong button on the audio panel," said Holloway. "He's telling the first officer, 'Hey we're going down which means, in short terms, we're going to descend to the altitude, and for the first officer it's not a big deal. Now, you take that out of context and you put it into the public's eye, at the same time the plane is descending now you have hysteria."
Jeff Ashburn has dealt with pressurization issues before.
"The pilots are very busy at this time taking care of the problem, and that's fine and that's good, but once you get control of the situation, certainly by the time you get on the ground or to the gate, you want to calm the passengers and communicate with them," said Ashburn.
Passengers say that never happened even though the pilot was able to correct the problem and make a safe landing.
"I think it was handled the way it should have been handled, the mistake that was made was miscommunication," said Holloway.
Southwest says the pilot handled the incident professionally and safely.
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."
There were 96 passengers and a crew of five on board the jet. All made it to Raleigh safely.
The airline is giving passengers a $200 voucher they can use for future travel.