NEW YORK (AP) — A tree at the World Trade Center site that was heavily damaged in the Sept. 11 attacks has been nursed back to health and replanted.Mayor Michael Bloomberg along with other city officials and Sept. 11 survivors replanted the Callery Pear tree Wednesday at the Sept. 11 Memorial Plaza.Bloomberg said the tree symbolizes the city and country's resilience.The tree was originally planted at the trade center complex in the 1970s. It was discovered in the rubble in October 2001 with snapped roots and a blackened trunk.The tree measured about eight feet high when it was taken to a Parks Department nursery in the Bronx to be nursed back to health. It now stands about 30 feet high.