The train's engineer saw Father Thompson move toward the train near the Whitford station in Exton. The engineer hit the horn and the air brakes but was unable to stop the train, police said.
The accident disrupted passenger service between Paoli and Thorndale for about three hours. The train's six passengers were bused to the Downingtown station.
Chester County Chief Deputy Coroner Norman Goodman said yesterday that he was able to confirm Father Thompson's identity through dental records and fingerprints.
Father Thompson was associate pastor at Mount Calvary Catholic Church in Forestville, Md., one of four parishes in suburban and southern Maryland he had served since his ordination in December 1992. Father Thompson completed theological studies at Theological College in Washington.
Cardinal Theodore E. McCarrick, archbishop of Washington, said yesterday that Father Thompson's depression had been ongoing.
"He was one of millions of Americans who struggle with this devastating illness every day, and his death was a terrible tragedy. He will be greatly missed," said Cardinal McCarrick.
Catherine Rossi, director of communications for the Archdiocese of Philadelphia, said men and women go into St. John Vianney Center voluntarily.
"It is not a locked facility," Rossi said.
She said that the center is licensed for 54 residents and was started in 1946. Sponsored by the Philadelphia Archdiocese, it is not a facility for substance abuse or alcoholism, Rossi said. Calls to the center were referred to Rossi.
"My heart goes out to Father Thompson's family, to his former parishioners, and to his brother priests for their loss," Cardinal McCarrick said. "I ask that each member of the archdiocese join me in prayer for them and for our other brothers and sisters who are suffering from depression.. . ."
Father Thompson is survived by his parents, Deacon Daniel and Ann Thompson of Chevy Chase, two sisters, and one brother. Family members were too grief-stricken to comment, Gibbs said.
A funeral has been scheduled for Monday at St. Rafael Church in Rockville, Md., Gibbs said.
Susan Weidener's e-mail address is sweidener@phillynews.com.