You must be referring to the Pershing accident in Germany. Killed two, IIRC.
Strangely, solid fuel rockets are much safer to store, stage and fire.
The one I was thinking of was caused by a solid rocket motor that was being tested by a crewmember. He was using a vendor-supplied test set to check continuity and electrical characteristics of an igniter squib when the propellant fired; since he was standing at the open end of the exhaust nozzle, the results were fatal.
I'm not sure what the missile type was, but I think it was a Nike.
This story was told to me by an older co-worker who worked on the test box, many years ago.