6.0 sudden loss of oil pressure

[magpie]

I have a 2007 2500hd with the 6.0l.  Driving home the other day the oil cooler line at the top of radiator blew off.  Truck shut down immediately.  Now that lines have been replaced, truck wont start.  Timing chain and tensioner are good.  Appear to have no compression in cyl. 1.  While trying to start if I hold it to the floor it will backfire.  This truck ran great with no knocking before all this happened.