They're probably suing stateside and hoping to recover damages from the Jamaican government via American juries. Apart from massive class actions that suck in significant amounts of ambulance chaser talent, it's a tough sell, and Crump doesn't strike me as a capable litigator
The article doesn't mention anyone suing anywhere yet, but there are a dozen or so reasons they couldn't sue the Jamaican government in the U.S. (foreign sovereign immunity, lack of personal jurisdiction, forum non conveniens... I could keep going). And the U.S. lawyers can't sue in Jamaica. So they were probably hired (if they were at all) just to drum up some publicity.