Stem Rot

This disease seems to be spreading across the garden and killing indiscriminately (tomatoes, peppers, beans, ...). The picture below is exactly what it looks like (with tiny orange dots below the ground) and kills the plant completely and quickly. As soon as you notice you have it, the plant is dead, if it's a small plant. A giant productive tomato plant takes a few days to kill. Major bummer.

What's the cause??