It could be the crew going out of hours, but also that the aircraft had built up delays during its previous sectors that day and would therefore arrive after a curfew (if LGW has one). But twice in a row is a real downer. Hope they get away tonight ... but don't necessarily expect to have answers from the crew or the local ground staff. I fear that once you buy a ticket, you may face this sort of delay and ultimate cancellation as part of the agreement you accepted when you accepted the company's terms and conditions ... not always visible. Might you have a legitimate claim under EU261? At least some reason would have to be given as to why the flight was cancelled, even if you don't ultimately gain compensation. Of course, the hot weather and thunderstorms might have had something to do with the delays .... which are not covered by any type of insurance as far as I know. Sorry that your relatives were delayed ... at least they were able to go home for the night? ... and hope that they'll be with you soon.