Some smoke. We had a 5 gallon bucket with water for most. But when picking up the remaining ones from the neighborhood I just started tossing them in the garbage as they seemed out (our kids had been spraying them with water after each finished too). Dug into the can and it was starting to spread. Sprayed it all down and filled the can up with water to that point. Moved it to our curb.
Learned my lesson and got off easy/lucky. Reading this thread helps cement the lesson...