There was the case several years ago of three aeroplanes declaring Mayday diverting into Valencia when Madrid had closed with un-forecast thunderstorms. And another that didn't call Mayday actually landed very low on fuel...
That one was not caused by the airline in question but by ATC. And it was funny that the "real" story of the A340 landing really short did not make news while the 737's which didn't were discussed widely.