Melted spray arm resulted in leaky dishwasher

Over Thanksgiving, the spray arm in my dishwasher apparently popped off and was partially melted. I remounted it inside the dishwasher, but the new hole was on the side of the arm. I think this resulted in water being sprayed directly against the door and not up through the top holes. It flooded my kitchen floor.

The spray arm pops on and off with plastic tabs (?) at the base. You can lightly pry with a butter knife or simply wiggle it off. The new one popped right on. Easiest repair EVER.