NORTH HAVERHILL, N.H. A former chief financial officer and senior vice president at Pittsburgh-based PPG Industries today admitted that he killed a pregnant woman, her fiance and their fetus in what he called a failed suicide attempt when he drove his pickup truck across a highway median into oncoming traffic. Robert Dellinger, who also is a former Sprint chief financial officer, pleaded guilty to negligent homicide for the 2013 deaths of 24-year-old Amanda Murphy and 29-year-old Jason Timmons, of Wilder, Vt.