With two presidents, the governor, mayor and thousands of families converged at the World Trade Center, police say they are ready to protect them. Dean Meminger was given exclusive access inside a special command center that's keeping watch on movement around the city.

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NEW YORK CITY, N.Y. -- From their new Joint Operations Center, the police department is monitoring numerous areas for suspicious activity. The main focus is Lower Manhattan as memorial events for the 9/11 anniversary are underway.

"FBI, secret service, Port Authority police, state police, they are all in our operation center,” said Police Commissioner Ray Kelly.

The latest technology is being used inside the $49 million center, which is also known as the JOC. City, state and federal agencies sit side-by-side with the NYPD to protect New York against a possible terrorist hit as well as monitor all other major situations.

"It is an information hub. What happens in the city comes into that location. It is then disseminated to the appropriate units, departments. It plays a very important role,” said Kelly.

Although the center has plenty of sophisticated computer systems and fast-moving information, police officials say one of the most important aspects at the JOC is the face-to-face interaction between various agencies.

For example, if something happens on an Amtrak train, a representative in the center can immediately bring various emergency agencies up to speed, including the military.

Those movements, of course, are behind closed doors, but there was plenty of movement for all to see Saturday, just hours before the anniversary ceremonies.

Police rapid response teams were zooming across Manhattan in a clear sign of force and presence.

Scores of tow trucks hit the streets to remove cars parked anywhere near the World Trade Center just in case they posed a threat. Thousands of police officers remain in the area to protect against any terrorist threat.

"We are concerned about the threat going into next week. Hopefully we will get more information from the federal government so that we can ratchet down our response," said Kelly.

For now, however, the NYPD will stay on a heightened alert.