NEW YORK (AP) — Familiar rituals of grief marked the seventh anniversary of Sept. 11 on Thursday as thousands paid tribute at the attack sites, the presidential candidates laid flowers at ground zero and children mourned parents they can barely remember. Sens. John McCain and Barack Obama called off their campaigns for the day, and in the late afternoon descended the long ramp into the pit of the World Trade Center site, bowing their heads and leaving the flowers in a reflecting pool. At the Pentagon, 15,000 people turned out for the dedication of the first permanent memorial built at any of the three sites where hijacked planes crashed. It includes 184 benches that will glow at night, one for each victim there. “Thanks to the brave men and women, and all those who work to keep us safe, there has not been another attack on our soil in 2,557 days,” President Bush said at the outdoor dedication. In New York, the crowd fell silent in a park just east of the trade center site at 8:46, 9:03, 9:59 and 10:29 a.m. — the times when two hijacked jets slammed into the buildings and the twin towers fell.