ValuJet had a history of accidents, faults and god knows what - nothing like Ryanair in the least.
...and that awful crash in the Everglades was brought about by the company's transporting undeclared oxygen canisters which caught fire in the cargo hold, the heat of which severed the link between the cockpit controls and the flaps/rudder.
valujet was wiped out in the US by a crash and ryanair's traffic and stock value would surely plummet in the event of one.
FWIW, Valujet changed their name to AirTran shortly after the accident and are still operating throughout the southeastern US and beyond.