I don't remember the exact details, but in the early 70's I was associated w/ a similar situation. If correct, the group split into two smaller groups - one leaving before the other. It was in the Laurel mountains in southern PA and fog can be a surprise guest. The other group's leader left the road in a foggy turn. About four to six bikes followed the glow of his tail light. Luckily no one was hurt - I suspect because the fog was so bad it limited their speed, but there was some damage So, it does happen...
