At 3 a.m. on April 13, 1919, Mounted Watchman Clarence M. Childress and his partner, Mounted Watchman Leroy D. Straw, were on duty near Monument 9, known as "The Island", near El Paso, Texas. The officers observed a man come near the line on the Mexican side and a few seconds later three men ran from the United States side into Mexico and joined the man waiting there. The group then moved several hundred feet into Mexico and a few minutes later seven men came to the line which at that point was marked by a barbed wire fence. Two of the seven held down the barbed wire fence with their feet while the other five, with sacks on their backs, crossed to the American side. The officers made a challenging run at the smugglers and the two who had remained on the line immediately opened fire while the other five dropped the sacks they were carrying and ran toward Mexico. The officers returned fire and all seven of the smugglers ran further into Mexico, disappearing over the mesa.
While the officers were pursuing the smugglers, Childress said, "I am hit and going to telephone." Mounted Watchman Straw proceeded to the point where the smugglers had abandoned their contraband where he remained, expecting Childress to return. When Childress failed to return to the scene within a reasonable time, Straw became concerned and proceeded to a house where a telephone was available. There he learned that Childress had been seriously wounded and was being cared for pending the arrival of an ambulance. An emergency operation was performed on Mounted Watchman Childress but he failed to recover. Death occurred at 9:10 a.m. on the morning of April 16, 1919.