NY1 VIDEO: At Citi Field, Mike Piazza and John Franco, who played for the New York Mets in 2001, led first responders onto the field for an emotional ceremony before their game against the Chicago Cubs. Each member of the Mets also escorted a member of Tuesday's Children onto the field.

The city police and fire departments and other emergency service took part, as did former Mets from the 2001 season.

Citi Field's predecessor, Shea Stadium, played an important role after 9/11, as it was used as a staging and recovery area, with supplies readied for rescue workers at the World Trade Center site. The stadium also hosted the first game in New York after the terror attacks.

Nearby in Queens, another 9/11 ceremony was held at the National Tennis Center before the women's final.