Flossmoor native Lt. Cmdr. Patrick Jude Murphy had served on nuclear submarines and had recently moved to New Jersey with his wife and two children.
He was a reserve officer who was at the Pentagon Tuesday when American Airlines Flight 77 slammed into the building, said his godfather, William Slavin, who shared a Chicago Heights dental practice with Murphy's father.
Murphy, 38, grew up in Flossmoor and graduated from Marian Catholic High School in Chicago Heights in 1981.
Murphy's sister, Kathleen Schweikart of Naperville, said Pentagon officials asked them not to comment about her brother's fate. "Right now, we're just waiting," she said.