Auxtank:
All very grim but there seems to be some confusion in that report about departure and destination, also:
"Video footage shared on social media showed how a fight broke out between several passengers over an hour into flight BA2159 from Gatwick to St Lucia.
The pilots continued the flight to Hewanorra International Airport in Vieux Fort despite the fighting in the cabin."
TBH that sounds odd to say the least and FWIW another UK tabloid media source has different timing, stating:
"Shocking footage shows the moment flight BA2159 from Gatwick to St Lucia descended into chaos as a brawl broke out between several passengers around an hour and 20 minutes from touchdown."
(my emphasis)