smelled burning, saw smoke

Driving to Fedex today:
Smelled like rubber burning, thought, can't be me.
Stopped at the light and smoke blew past my window. Hmm might be me.
Said, I'll check it out at my destination.
Got there and went to pull the brake handle. Oops! Left her on.
But I did discover only one brake was smoking, so the other is probably loose.

That guy in the mirror does dumb stuff lol