2002 Chrysler PT Cruiser Oil Light and Car Died

The car has had a history of overheating, but no other problems. During the ride to work this AM there was a strange rattle every time the engine was given gas while traveling at about 60mph. About a minute after the rattle started, the oil light came on, we pulled over, and in the process of pulling over the car died. With the hood popped, there was oil on the top of the engine right near the fill and I couldn't get the fill cap open. It looked to be right next to a spark plug, but maybe that was just coincidence. When I checked the oil it was just at the bottom of the dip stick. There was no trail of oil behind the car. The engine would not turn over again after stopping for a little while and just trying it (even though we knew the car was undrivable). My guess is something major is wrong. The timing belt has never been replaced, at 140k miles I think that is a very good possibility of what the rattle was and engine seizing. Any other thoughts? Thanks.