2004 Pontiac Grand Prix GT2 overheated, shut off while driving, now will not fire

Yesterday I was driving my Grand Prix home and noticed the vehicle was
running rough, but I never saw the temperature gauge notify me it was
overheating. Eventually, as I was driving, I heard what I would describe as a
metal fork banging back and forth in a tin can coming from the engine. Right
after that started, my RPM dropped to zero, I lost power steering, and the
engine seemed to have cut out. I pulled over, and it would not start. The tow
truck driver informed me the car had overheated, and I seem to be missing a
large amount of coolant, though I never noticed any smoking coming from
the radiator or the engine. I towed the vehicle home, and left it overnight to
cool down. This morning, I attempted to fire it, and it barely started to crank
for about a half-second to a second, then dead silence. Next attempted
crank, a simple click. I figured the battery may be dead, since I sat with the
battery running the A/C until the tow truck driver arrived. But after charging
the battery, it still didn't fire. I tried jumping it, it still didn't fire. If I repeatedly
try to start it, after the first attempted crank, when I attempt to crank it is one
simple click. If I come back to it after a few minutes, it will attempt to crank
(again, only for a half second), and then right back to the single clicks. I was
hoping somebody would have some insight, I am hoping this engine is not
shot, as this car is on a loan.