Lose of power, now won't crank

I have a 2002 Ford Explorer, V6, 135,000 miles, that was running fine until we took a trip recently. While running down the interstate at 70 mph the engine suddenly lost power. There were no warning signs, no lights came on, and the motor had not been missing or making any type of noise. Once safely off the side of the road, we tried cranking it and it just sputtered and acted as though it wasn't getting any fuel- and I had ½ tank. After we got it towed back to the house we ran a series of tests to eliminate/isolate the problem, these included dropping the caditilic converter, and changing the crank shaft sensor. A hand held diagnostic computer was hooked up and the code suggested the problem was with the coil pack. This was replaced to no avail. Upon contacting our mechanic at the Ford place he reminded us that the front timing belt was changed @ 100000 miles, but that they didn't touch the one in the rear. A compression test read: #1- 90#, 2- 0#, 3- 0#, 4- 0#, 5- 0#, #6- 130#. We're afraid that we're going to have to tear into the motor, can you give us any suggestions on where to go next to make this a last resort?