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.'"