The Boeing 777-300ER was about 10 hours into its flight and midway through meal service when it hit turbulence while flying over Myanmar’s Irrawaddy Basin, according to the airline.

Andrew Davies, a passenger onboard flight SQ321 who was traveling to New Zealand for business, told CNN’s Erin Burnett that it had been a “perfectly normal” flight when the seatbelt sign came on and seconds later “all hell broke loose.”

“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.

Davies said he realized the “gravity” of the turbulence when he turned around, describing several passengers with gashes on their heads, including one with “blood pouring down her face” and an elderly passenger in “severe shock.”

“There was so much screaming,” he said.

Video and images from inside the aircraft showed the extent of the damage, with overhead compartments smashed open and emergency oxygen air masks hanging down from the ceiling. A photo of one galley showed a section of the ceiling open with parts of the plane’s interior hanging down. Trays, containers, plastic bottles and hot beverage pots can be seen strewn across the floor.

A 73-year-old British man died in the incident from a suspected heart condition, the General Manager of Bangkok’s Suvarnabhumi International Airport Kittipong Kittikachorn said Tuesday, adding that the autopsy process was still ongoing.

The man was later identified as Geoff Kitchen, who was described as “always a gentleman with the utmost honesty and integrity” by the Thornbury Musical Theatre Group (TMTG), an establishment where he worked for over 35 years.

The British Foreign Office told CNN it was supporting the family of a British passenger who died on a Singapore Airlines flight.

Davies, who was seated toward the front of the plane, said he helped tend to Kitchen, who was seated behind him.

“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 lay him on the floor so that some medical profession(als) could administer CPR,” Davies said, adding the passenger was administered CPR for about 20 minutes.”