Come next Wednesday an epochal event will take place in New York City: 4 World Trade Center -- 72 stories tall -- will open on the World Trade Center site, helping to restore a long-missing sense of community to a vital part of our city. The tower will include 53 floors of office space and five floors of retail.

Its opening means that for the first time since 9/11, New Yorkers will be able to use the 16-acre site once known as Ground Zero as a centerpiece for their daily lives.

Progress is one word for that. Healing is another.

When reconstruction on the site nears completion in the next few years, the hope is that the new space will provide a much-needed common center that connects the Financial District and Battery Park City as a single, bustling business and residential district.

But it's crucial to do the job right. Still unresolved is an important question. Security must be sufficient -- and then some. All New Yorkers would agree on that. Yet at the same time, it mustn't be too onerous.

Greenwich and Fulton streets -- which haven't crossed the site since the Twin Towers went up -- will reopen. The talk is that taxis, livery cars and delivery vehicles can go through NYPD checkpoints, which makes sense.

But what about the free flow of foot traffic across the site -- vital to the health of any neighborhood? Will downtown's millions upon millions of tourists, workers, residents and students be allowed to use streets through the WTC -- and the amenities around them -- with relative freedom? Will residents be able to meet visitors at iconic locations there the way they meet friends under the clock at Grand Central?

The answer must be yes. The owners of Brookfield Place (formerly the World Financial Center) recently opened a stunning tunnel under West Street linking Battery Park City to the new PATH station, designed by Santiago Calatrava and opening in 2015. 1 World Trade Center (first called the Freedom Tower) will be complete in early 2014.

A great neighborhood is rising before our eyes.