The cause could also have been a bad receptacle that you were plugged into.
If the connections are loose or worn in the receptacle, it won't make a good connection with your plug. Heat can build up, and damage your plug.
When I plug into a 30 amp pedestal, if the receptacle seems loose, I'll use my 50 amp adapter and plug into the 50 amps (if there is one). Generally, the 50 amp receptacles get less use and are in better condition than the 30 amp receptacle.
2001 Coachmen Mirada (Ford F53 6.8L V10) - Toad 2001 Civic
It won't do MACH 2, but I can get a sandwich and take a pee.