One person was killed, and more than 70 others were injured, after a Singapore Airlines flight from London to Singapore encountered "severe turbulence," the airline and Thai officials said Tuesday. 

After flying through the turbulence, the flight made an emergency landing at Bangkok's Suvarnabhumi Airport at 3.45 p.m. local time, according to an airline statement. 

A 73-year-old British man died in the incident, likely from a heart attack, Kittipong Kittikachorn, the director of Bangkok's Suvarnabhumi Airport, told a press conference. Several others suffered severe head injuries. 

Kittipong said the plane flew into an "air pocket." 

"There were lots of passengers who couldn't walk and we rescued them from the plane," Kittipong said, adding that the air pocket must have been "quite severe from looking inside the plane."

The Boeing 777-300 aircraft was carrying 211 passengers and 18 crew members.

Aircraft dropped 6,000 feet in five minutes, data shows

A passenger who spoke to Reuters news agency said turbulence caused passengers not wearing seatbelts to slam into overhead cabins. 

The airline said the plane encountered turbulence while flying 11,300 meters (37,000 feet) above Myanmar's Irrawaddy Basin.

According to data from FlightRadar 24 cited by Reuters, around 11 hours into the flight, the aircraft dropped from an altitude of 37,000 feet to 31,000 feet (around 11,277 meters to 9448 meters) within just five minutes.

"Suddenly, the aircraft starts tilting up and there was shaking so I started bracing for what was happening, and very suddenly there was a very dramatic drop so everyone seated and not wearing seat belt was launched immediately into the ceiling," Dzafran Azmir, a 28-year-old student on board the flight told Reuters.

Local emergency crews from Bangkok's Samitivej Srinakarin Hospital were dispatched to the airport to transfer injured people off the runway for treatment.

The hospital said 71 people were sent for treatment, with six of them severely injured. 

Singapore authorities said another plane would be sent to Bangkok to transport uninjured passengers onward to the city-state's Changi airport.

Singaporean government 'deeply saddened' 

Singapore's Transport Minister Chee Hong Tat said in a Facebook post that the Singaporean government would provide assistance to the passengers and their families.

"I am deeply saddened to learn about the incident onboard Singapore Airlines flight SQ321 from London Heathrow to Singapore," he wrote.

Singapore's transport ministry said it would send investigators to Bangkok.

Boeing also extended "deepest condolences to the family who lost a loved one" on the Singapore Airlines flight, and added that "our thoughts are with the passengers and crew."  

Singapore Airlines also offered "its deepest condolences to the family of the deceased." 

"Our priority is to provide all possible assistance to all passengers and crew on board the aircraft.

It added that it was working with the Thai local authorities to provide the necessary medical assistance.

One of the world's leading long-distance carriers, Singapore Airlines has not had a fatality happen on one of its flights since 2000, when a plane crashed on a runway during takeoff in Taiwan, killing 83 people. 

mf/rmt,wmr (AP, AFP, Reuters)