Sizzle and burn, especially when there was an electric load, could have been an almost open contact. (Corroded away, shaken loose, whatever.)
These arc, and generate heat.
(And, btw., would never trip an GFCI, because the current flowing is not flowing to ground.)
The load of a space heater and an iron should not be enough to fry even a semi-decent installation, something was wrong.
For the installation being as good as before, it should be enough to just open the box and replace whatever is burnt with same quality home depot parts.
For your entertainment:
If the burn is somewhere where current should have been flowing, it was an open contact.
If it is through something that should not be, but was connecting life wire to ground, it was a ground fault.
No difference for the repair: Replace what is burnt, and you are as good as you were before.
Ground fault protection does not primarily prevent fires; it prevents electrocutions. So while having it is a brilliant idea, but it would not necessarily have prevented your sizzle.
Also, in case you are considering installing it, it does not have to be in the power outlet box; can be in the main breaker box, too, if you have 3-strand wiring.
I liveaboard. It's a 1985 Catalina 30. I was up at 4:45am ironing my work clothes, running the small space heater, and had the speakers on listening to NPR. All of these were plugged into a power-strip, which was plugged into an outlet.
Anyways, a couple minutes into waking up and getting ready for work, I heard "zzz-zzzz-zzzzzzzz-zZZZZZzzz" and thought "This is a weird sound-bite for them to use-" until I realized there was a little spark at the wall outlet and everything stopped working. (process of about 2 seconds)
So. What now? Neither outlet works. I think - with zero electrical knowledge - that I could just replace the outlet for a few dollars at home depot, plug the wires back in, and be on my way. Is this correct, or should I look deeper down for the source of the problem?
I was advised by the surveyor to replace them with GFCI outlets, but the actual wall-boxes are not large enough to fit the GFCI's. Maybe because of the ease of access I can cut out this one and install a GFCI. This is the outlet I use primarily for things because it's easiest to reach.
Here are views of the outlet(burn). Front, side (access), and back (wire)
Hopefully the collective sailnet wisdom will have had experience and solutions with a problem like this. - Thanks ahead for your input