1998 Camaro 3.8 Lifter Collapse

Recently I got in my car and started it to a loud knocking noise - as if the engine had no oil. Checked the oil, and it was maybe 1/4 quart low. Put a little in it anyway, and tried again, still knocking. This was sudden, I had driven the car 3 days before, with no problems at all. Today I found out that the lifters had collapsed. My dad was a GM master tech before he retired, and he said he'd never seen one do what mine did, not and have ALL the lifters collapse like that. The car only has 86k miles on it, and I was just wondering if anyone else had this problem with their series II 3800's.