But this is what Lionel Lenz knows for certain: His daughter, Mary Lenz Wieman, 43, an Aon Corp. marketing executive who grew up in Arlington Heights, had gathered 40 people for a meeting about a new client Tuesday morning on the 105th floor of the World Trade Center's south tower.
Lionel Lenz, his wife, Marianne, and their two sons drove from Arlington Heights to New York last week to wait with Wieman's husband and three children in their Rockville Centre, N.Y., home.
Lionel Lenz sees no point in making a missing poster for his daughter. He is sure she is dead.
The family has filled out the paperwork to identify her. She wore a blue square ring on her right hand, with the initials "SHM," for Sacred Heart of Mary High School, from which she graduated in 1976.
On Sunday, Lionel and Marianne Lenz went to the armory in New York to give DNA samples. They brought hair from their daughter's hairbrush.