Here's how much Singapore Airlines could be on the hook for after turbulence left one dead and dozens in the hospital

• One man died and more than 100 passengers were injured after a disastrous Singapore Airlines flight.
• The injuries could lead to an an expensive lawsuit against the airline.
• The injured passengers could be entitled to $170,000 or more thanks to a 1999 treaty, SCMP reported.

Passengers who were severely injured during extreme turbulence on board a Singapore Airlines flight earlier this week could reap six-figure payouts or more, South China Morning Post reported.

A 73-year-old British man died during the Tuesday flight from London to Singapore after the Boeing 777 aircraft dropped hundreds of feet before stabilizing mid-flight. More than 100 other passengers were also treated for various injuries, making it one of the worst turbulence incidents in recent history. 

Several passengers suffered traumatic injuries, including paralysis, skull and back trauma, and brain injuries, The Associated Press reported.

Damages won't be awarded until an investigation is completed, an aviation lawyer told South China Morning Post — a process that could take years. But the injured passengers on board have a means to seek payouts through a more than two-decade-old treaty.

The Montreal Convention, or MC99, is an international agreement that governs global airline liability in passenger death and injury cases. The treaty was created in 1999 to establish a more unified set of airline policies that can protect passengers and hold airlines accountable, according to the International Civil Aviation Organization (IATA). Part of the agreement stipulates that passengers who suffer injuries caused by an airline can recover up to $170,000, the IATA wrote in a report.

"MC99 is designed to be a single, universal treaty to govern airline liability around the world," the IATA wrote.

One unnamed woman who flew with Ryanair in 2020 was paid $33,000 by the Irish budget airline after she broke her leg when exiting the aircraft. The woman cited the Montreal Convention in her claim.

Another airline passenger, citing the treaty, sued Delta earlier in May, claiming he broke a rib after the armrest collapsed when he leaned on it. The passenger is asking for $1 million since he also accused Delta of negligence.

A Delta spokesperson did not immediately return a request for comment sent outside working hours.

Despite the 1999 treaty's $170,000 limit, Peter Neenan, an aviation lawyer, told the South China Morning Post that victims who experienced similar injuries as the Singapore Airlines passengers reached "easily into seven and sometimes eight-figure claims."

The compensation amount, however, could only be determined after the investigation into the flight is done, he told the publication.

One passenger on the relief flight from Bangkok to Singapore told The Straits Times that an airline staff member offered passengers monetary compensation. He told the outlet that a staff member gave him an envelope with 1,000 Singapore dollars, or about $740.

"(The staff member) said that the money was like … an apology," he told the Straits Times.

After the deadly flight, Singapore Airlines announced that it would no longer serve meals when the seatbelt light is on.

A spokesperson for Singapore Airlines did not respond to a request for comment.