No oil pressure

[FarmerFrank]

Being that pressure is a measure of resistance to flow....this is entirely possible....

So blown out cooling squirter or spun shaft....any other spots like oil galley plug may have come out inside engine....that could do it to.

You guys both beat me to it. Pumps do not create pressure. They create flow and resistance to the flow creates pressure.

So it may be possible for a large internal leak.

Or your oil pump took a crap.