no oil pressure

if the engine was running with zero oil pressure, most likely either the tip of the intermediate oil pump drive shaft sheared off, or the oil pump rotor shaft broke, or what was previously mentioned: a lifter popped out of its' bore. There are some other scenarios possible. Was there any "spirited' driving involved prior to the loss of oil pressure? Or was there any engine servicing performed prior to this incident? Please give us a follow-up on what you find out.