One passenger died and 30 others were injured on a Singapore Airlines flight that encountered severe turbulence, officials reported on Tuesday. Experts note that fatalities due to turbulence are rare, even as researchers warn that climate change may be contributing to more extreme turbulence events.

Since 2009, the National Transportation Safety Board (NTSB) has not documented any turbulence-related fatalities on large commercial aircraft, such as the Boeing plane that experienced sudden severe turbulence over the Irrawaddy River in Myanmar at 37,000 feet.

The incident resulted in the death of a 73-year-old passenger who had pre-existing medical conditions, possibly due to cardiac arrest. Additionally, at least seven passengers were critically injured, according to Kittipong Kittikachorn, general manager of Bangkok’s Suvarnabhumi Airport, who addressed the media on Tuesday.

The cause of the turbulence is under investigation. Singapore Airlines reported that the flight, traveling from London to Singapore, encountered severe turbulence about 10 hours after departure.

While fatalities from turbulence are infrequent, severe turbulence encounters are not uncommon, stated Larry Cornman, a physicist and project scientist with the U.S. National Science Foundation’s National Center for Atmospheric Research. “Often, in situations like this, it’s just wrong place, wrong time,” said Cornman, who researches small-scale atmospheric motions that can endanger aircraft.

Despite the vast number of flights conducted each year, turbulence has resulted in 185 serious injuries from 2009 to 2023, the latest year with available data, according to the NTSB. The agency, which requires airlines to report injuries and fatalities, defines a serious injury as one necessitating more than two days of hospitalization, involving internal organs, or resulting in bone fractures, severe burns, hemorrhages, or damage to nerves, muscles, or tendons.

From 2009 to 2022, 129 crew members and 34 passengers were reported injured due to turbulence-related incidents. Turbulence-related fatalities can result from heart attacks or head injuries if a passenger’s head strikes the ceiling or is hit by falling luggage, Cornman explained.

“Anything that could cause a death on the ground can certainly cause it inside an aluminum tube at 35,000 feet,” he said, emphasizing that passengers wearing seat belts should still feel safe. “These large transport aircraft are built very robustly. They will not fall apart or plummet from the sky due to turbulence,” Cornman added.

Sara Nelson, president of the Association of Flight Attendants-CWA, mentioned that initial reports suggest the Singapore flight encountered clear-air turbulence, which is particularly hazardous because it is invisible and undetectable with current technology.

“One moment, you’re cruising smoothly,” Nelson said. “The next, passengers, crew, and unsecured items are being thrown around the cabin.”

Nelson and researchers point out that incidents of clear-air turbulence — difficult to forecast and avoid because it is not associated with storms — are on the rise due to climate change.

A 2023 study published in the journal Geophysical Research Letters found that severe clear-air turbulence over the North Atlantic Ocean increased by more than 50% from 1979 to 2020. This research suggests that as climate change progresses, such turbulence events may become more frequent, posing greater risks to air travel safety.