The conditions that could cause a no-start on a 6.0L are long and diverse. It is not uncommon for it to be high-pressure oil related. The one that got me, and I’ve heard is not uncommon is a blown internal o-ring in top of an injector, where the high pressure oil rail inserts into the injector. Mine blew out under hard acceleration, pulling a 5th-wheel onto the interstate. But I have heard of them just failing for no apparent reason; pull up to a 7-11 for a coffee, come back out, and no-start.
A (relatively) easy way to check is to pull the ICP sensor and valve covers. Apply air pressure to the ICP port and look/listen for air/oil bubbling. I’ve also heard of the HPOP discharge line(s) breaking, leading to a no-start.
Good luck.