[meyer]

Explosion at Hoover appears to me to be a transformer, possibly for one of the many generators there.
That’s my take. The fire is the insulating oil burning.

[HippyLoggerBiker]

Middle of the diagram where it says 'Powerplant'

[Steven W.]

ThankQ for that assessment! WWG1WGA :)

[little jeremiah]

I read that the water levels in Lake Mead are extremely low. Could that have anything to do with the transformer blowing up/catching fire?

We have transformers on the power poles doing that a lot around here. Often in high heat or when trees/branches fall on the lines. Or some idiot crashes into a pole. All for these happen frequently around here.