Brad Steiger, in his book 'STRANGE DISAPPEARANCES' (Lancer
Books., N.Y. 1972) related the following (MIB-related?)
incident:
"...at sundown on February 12, 1953, witnesses told police
that they had watched an automobile enter the throat of a storm
drain near Willowbrook and Greenleaf Avenues in Los Angeles.
Officers arrived on the scene within ten minutes, and according
to the Los Angeles HERALD AND EXPRESS, they followed the fresh
tire-tread marks into the tunnel for seven miles. Other
policemen and flood control district workers continued the search
for the automobile by dropping through manhole covers.
"The trackdown continued until midnight when, seven miles up
the storm drain, THE TRACKS VANISHED. 'HERALD AND EXPRESS'
newsmen who had accompanied the police on the incredible search
up the tube were witnesses to the fact that: 'In the muddy silt
covering the floor of the drain, the tire-tread marks were sharp
and fresh. Then no more tracks.'"