black smoke then truck dies cranks but wont start

Today my 2006 6.0 shut down after a series of hard uphill pulls while pulling a 38' fifth wheel camper. Started blowing black smoke like if I had a programmer installed (I dont!) While pulling hard uphill it startebecoming sluggish and losing power, and blowing a good bit of black smoke, once I started down hill I got off the accelerator and it died. I coasted all the way down into a service station.
Truck spins super fast but no fire!!!!
I removed fuel bowl cap, turned key, and we have fuel filling up.
I removed EGR Valve and checked to see if stuck open. Its not, cleaned it and reinstalled
Shot a little starting fluid into intake. No start
Oil level. Good
Coolant. Good
Also did long crank, oil pressure gauge jumps to mid range.

I've been reading up, IS IT POSSIBLE EMERGENCY FUEL SHUT OFF SWITCH FLIPPED?

What is next step? Remember hard uphill pulls, black smoke, down hill truck dies!!!

Where is the shut off switch located so I could check it?
Thanks

Right front under the plastic kick panel on right side, dont think that's your problem but the best of luck.

Ok thanks im going check.

Anyone else???????
ok NOT the emergency FUEL SHUT OFF SWITCH

Turbo would explain the smoke, but not dying...

do u hav anyway to monitor icp? u could try starting with unplugged icp sensor. u need some gauges to diagnose problems.

Kinda late to repost the actual fix to this problem.

Problem was oil line with quick connect on back of engine, it had popped off. Replaced oil line with no quick connect, truck runs great again. Thanks for all who tried to help.