A Singapore Airlines flight was forced to make an emergency landing due to a loss of cabin pressure.

The Airbus A380 was flying from London to Singapore, but had to make an unplanned emergency landing in Azerbaijan due to the cabin pressure issue. Oxygen masks were deployed during the flight, forcing the plane to land at Baku airport. It landed without issue. The flight was carrying 467 passengers and 27 crew members, the BBC reports.

According to Nathan Phelps, an electrical supervisor from south Wales who was on the flight, the pressure started to drop suddenly when the plane was at 38,000 feet, the BBC says.

"I literally thought we were all going to die. There was no warning, the plane just went into a deep descent, the masks dropped and you automatically thought we were going to crash. There was no other rational thought really. You couldn't really look at it optimistically because you had never experienced anything like that before," Phelps said.

A replacement airplane was sent to Baku and is scheduled to arrive on January 7 to take the stranded passengers to Singapore. The airline also sent staff from Istanbul and Moscow to provide assistance to passengers in Baku.

Despite the airline doing what it could to assist passengers, many took to social media to complain about the wait. Some said they had to sleep on cold steel benches and that the airport doesn't have food.

Singapore Airlines issued an apology on Facebook, saying, "We sincerely apologise to affected customers for the inconvenience caused by the diversion and the lengthy delay encountered at the airport in Baku."

Airbus says it is trying to provide assistance to the airline. Singapore Airlines has 19 Airbus A380s