How scary!

I'm in my 03 A4 3.0 Cabrio yesterday, on the freeway. I turn on the cruise control, and as soon as I take my foot off the gas, the car completely powers down. Needles drop, no power steering. It was pretty scary and I'm glad I pulled over safely. The car started up fine when I tried to restart.

Any idea what would cause this? Is it related to the cruise control or was that possibly just a coincidence.

Car has about 67K.

 

to shut down quickly like that it would have to be an intermittent problem with main power or main controls. either ecu or fuse box/wiring connections