I replaced the outlet and it seemed to work ok after that. I also replaced the fried plug on the extension cord. It's a heavy gauge cord but don't know the exact gauge.
The other day I tried to use the same outlet, same cord with an electric hedge trimmer and the plug began smoking where it connects to the trimmer. Also now the trimmer is on all the time, whether you depress the trigger or not.
I haven't tried this cord in another outlet yet, kind of wary of frying another electric tool. Does this sound like an outlet problem, or an extension cord problem. I got the screws good and tight on the replaced cord plug, also got them tight on the new outlet in the house, did not use the "backstab" holes.