Trying to find out if my new hot water heater is shot
The red button you pushed on the hot water heater was probably what is called a "piezo-electric" ignitor. It's normal for it to make a snapping sound and then pop back out. It sounds like you just lost the pilot light.
That being the case, do this:
Turn the gas valve on the hot water tank to the "off" position - it should be silver in color and down low on the tank. You may have to push it down to do this
Leave it off for about two minutes or so
Rotate the valve back on to the "Pilot" position
Hold down the pilot gas valve - it should be red and immediately to the left of the main gas valve.
While holding the pilot gas valve down, push the other red button to the right of the main gas valve - this is the piezo ignitor - push it several times in a row quickly
The gas pilot light should light
You can stop pushing the ignitor now, but continue to hold down the gas pilot valve (the one just left of the main gas valve). Let this valve up after about another 20 seconds or so.
Now rotate the main gas valve to the "on" position
Listen carefully - you should hear the main gas light and feel heat at the water heater flue outlet on top - don't touch it with your hand - you could get burned
If no luck, repeat the process until the heater re-lights
TIP - the instructions for re-lighting the pilot should be written on the heater
Just a potential diagnosis - the thunder clap, if as close as you describe, may have been intense enough to create what is known as a "draft inversion" that may have snuffed out your pilot light. The air pulse came down the flue pipe.