1995 Ford Aspire engine cranks but will not start

I bought a 95 ford aspire that was rolled over. Since the roll over, the inertia switch has been reset and the car has been driven. When my dad was working on the rear quarter panel, he unhooked the filler tube to the gas tank so he could grind on the metal and when he hooked it back up, the car will no longer start. There doesn't seam to be any power going to the fuel pump on top of the tank. Can an inertia switch just go bad? Should there be juice to the fuel pump when ignition is on? I am baffled beyond all hope. I have heard everything from the tank lost pressure to the inertia switch is killing the power to the fuel pump. Please let me know where to start of what is possible. Thank you