PITTSBURGH (AP) — An Allegheny County man has admitted he sabotaged railroad signals. Twenty-six-year-old William Brown of Elizabeth on Monday pleaded guilty to two counts of terroristic attacks and violence against a railroad carrier and mass transportation on land. Federal prosecutors say in November 2017 Brown detached four railroad signal antennas near Braddock and caused a complete signal failure by cutting cables. Prosecutors also say he severed signal wires near McKeesport. Brown faces up to 20 years in prison and a fine of up to $250,000 when he is sentenced in May.