Singapore Airlines flight SQ321 departed London on Monday at 10:38 p.m. local time, and encountered severe turbulence en-route, Singapore Airlines said.

At least one person died, with several others injured.

The Boeing 777-300ER — with a total of 211 passengers and 18 crew on board — was diverted to Bangkok and landed at 3:45 p.m. local time.

Passengers on the Singapore Airlines flight that hit severe turbulence on Tuesday described a sudden, dramatic drop as “all hell breaking loose”.

At first, “the flight was perfectly normal,” said passenger Andrew Davies, who was traveling to New Zealand for business. He described the flight as “quite smooth … I don’t remember any turbulence at all.”

Flight SQ321 was cruising at 37,000 feet from London to Singapore when flight tracking data shows the plane dropped sharply before climbing several hundred feet, then repeated the dip and ascent, for about a minute.

Many passengers were having breakfast at the time of the incident.

Then, about nine or 10 hours into the roughly 13-hour flight, he was watching a movie when he saw the seat belt sign light up – so he put his seat belt on. “Thank goodness I did because within moments of doing that, all hell broke loose,” he told CNN.

“The plane just felt like it dropped. It probably only lasted a few seconds, but I remember vividly seeing shoes and iPads and iPhones and cushions and blankets and cutlery and plates and cups flying through the air and crashing to the ceiling.

“The gentleman next to me had a cup of coffee, which went straight all over me and up to the ceiling,” Davies said.

Images from the plane afterward show the cabin in disarray, with papers, cups and water pitchers scattered on the floor, and ceiling panels and piping hanging loose.

Davies was sitting toward the front of the plane and witnessed some of the injuries sustained by dozens of passengers – including Geoff Kitchen, a 73-year-old Briton who died on the flight.

“That gentleman was sitting right behind me,” he said. “Lots of people needed some help but we tended to this gentleman, and I helped carry him, get him out of the seat, and we laid him on the floor so that some medical professions could administer CPR.”

Kitchen was given CPR for about 20 minutes, said Davies. Meanwhile, he said, “there was so much screaming,” and people’s injuries were evident; when he turned around, he saw one passenger with “a big gash in her head and blood pouring down her face,” and another elderly passenger in “severe shock.”

Another passenger, 28-year-old student Dzafran Azmir, told Reuters that the aircraft had begun “tilting up” and shaking.

“Very suddenly there was a very dramatic drop so everyone seated and not wearing a seatbelt was launched immediately into the ceiling,” he told Reuters. “Some people hit their heads on the baggage cabins overhead and dented it, they hit the places where lights and masks are and broke straight through it.”

Azmir added that the whole thing was “really, really quick – which is why I think nobody could really respond to it.” People didn’t have time to react, he said – there were passengers in the plane bathrooms and air crew still standing when the turbulence hit.

The plane was diverted to Bangkok after the incident, which injured 104 of the passengers, according to an update at Wednesday lunchtime from the Samitivej Srinakarin Hospital, which treated many of the travellers.

Those injured on the flight included citizens from Australia, Malaysia, the United Kingdom, New Zealand, Spain, the United States and Ireland, the hospital said in an earlier update.

Samitivej Srinakarin Hospital said 20 travellers remained in intensive care units on Wednesday.

Josh Silverstone, one of the passengers on the Singapore Airlines flight, described feeling “happy to be alive” as he was leaving Samitivej Srinakarin Hospital on Wednesday evening.

Speaking with journalists on his way out, the 24-year-old British citizen said he had suffered a cut on his eye and a chipped tooth in the turbulence.

He also said that after the incident had taken place, he had let his mother know he was okay by purchasing an in-flight Wifi package for the first time in his life.

Silverstone described the aftermath of the emergency landing in Bangkok, saying he started vomiting, which prompted him to look for medical care.

According to Silverstone, there are still several passengers being treated at the hospital, many apparently with spinal injuries and in a much worse physical state than he is.

Of the 211 passengers and 18 crew on board the original flight, 143 were transported via a relief flight to Singapore, where they landed early Wednesday morning, according to Singapore Airlines CEO Goh Choon Phong in a video message released on Facebook.

The remaining 79 passengers and 6 crew members are still in Bangkok, including those receiving medical care, and their family members. – CNN