The Justice Department said Monday that it had taken down several thousand documents and "media" that may have inadvertently included victim-identifying information.
The center will also be available for victims of Saturday's mass shooting that killed a 9-year-old girl.
A family of four, including a 2-year-old and 3-month-old, was killed Saturday when a vehicle crashed into a San Francisco bus stop. Now, family is donating the infant's organs.
Some 1,103 victims, or 40% of those who died in the 2001 attacks, remain unidentified.
A Christmas tree on the city's Southwest Side is helping families pay homage to victims of violence in cases that have never been closed.
Joe Schilling's loved ones believe he chose to stay behind at his apartment complex with several elderly residents who were unable to evacuate due to mobility issues.