Sweeping Security Effort for 9/11 Events

Ground Zero has massive police presence and stringent security measures

To fortify New York and Washington this Sunday, federal and local law enforcement officials are piling security plans atop security plans, making it not just the 10th anniversary of the Sept. 11 attacks, but also a milestone in a decade-long state of alert.

The defense portfolio includes thousands of New York and District of Columbia police officers, including divers, bomb technicians and counter-snipers; National Guardsmen; and F.B.I. intelligence analysts. The commemoration Sunday at the site where the World Trade Center was destroyed, and where a new memorial will be unveiled, will be attended by President Obama, former President George W. Bush and other dignitaries. President Obama will visit the Pentagon’s 9/11 memorial later Sunday.

Plans for the show of force stretch back at least to May, when a notebook filled with Osama bin Laden’s musings about a possible terror strike on the anniversary of the attacks was discovered in his compound.

But they intensified last week upon word of a new threat.