What sound (Onomatopoeia) does big lights shutting off sound like

I'm writing a story about a paranormal tornado and the story starts at a basketball game, but when the lights shut off and the warning sirens start, I don't know what sound effect (onomatopoeia) to use. Could you help me find something?

Solution 1:

Assuming that the question is asking along the parameters that I believe it is, then "thunk," "clunk," and "clank" convey how much treble is in the sound, from least to most. "Thud" has also been suggested, which conveys a less abrupt cessation to the sound.

Solution 2:

When a large bank of lights (or any other large-scale electrical phenomenon) is shut off, normally transformers shut down and that makes a loud "clunking" sound, like a large metallic object has just been dropped into its position in a much larger machine. Which is pretty close to what happens.