According to an Associated Press story:
Egan didn't know exactly what had happened in lower Manhattan that morning as he and his priest-secretary hurtled through the city. He couldn't decipher the crackle of the police radio and didn't have access to news. Giuliani first said he was sending Egan to provide support at a makeshift morgue on the city piers, then redirected the cardinal to St. Vincent's Hospital, so he could tend the injured.
Within 90 minutes, Egan would be standing in the doorway of St. Vincent's looking south to Wall Street as the World Trade Center crumbled. He would spend the next several days anointing the dead, distributing rosaries to workers as they searched, mostly in vain, for survivors, and presiding over funerals, sometimes three a day.
"For about five or six years, monsignor and I wouldn't talk to anybody about it," said Egan, referring to his priest-secretary, Monsignor Gregory Mustaciuolo, who was with him in the days following the attacks. "It was too much of a horror."