BANGKOK (AP) — A Singapore Airlines flight hit severe turbulence over the Indian Ocean and descended 6,000 feet (around 1,800 meters) in about three minutes, the carrier said Tuesday. A British man died and authorities said dozens of passengers were injured, some severely.

An airport official said the 73-year-old man may have had a heart attack, though that hasn’t been confirmed. His name wasn’t immediately released.

The Boeing 777 flight from London’s Heathrow airport to Singapore, with 211 passengers and 18 crew members aboard, was diverted and landed in stormy weather in Bangkok.

British passenger Andrew Davies told Sky News that the seatbelt sign was illuminated but crew members didn’t have time to take their seats.

“Every single cabin crew person I saw was injured in some way or another, maybe with a gash on their head,” Davies said. “One had a bad back, who was in obvious pain.”