The J. Joseph Moakley Federal Courthouse, on the edge of the waterfront and close to Logan International Airport--the point of origin for two of the four planes used in the attack--was one of the first buildings shut down. Because it is largely occupied by federal employees, it was considered a potential terrorism target. US marshals carrying machine guns patrolled the perimeter of the building. The State House and all state courts were closed, as were all federal buildings in the state. The John Hancock building, the Prudential building, high rises along the waterfront and in the Financial District--buildings that are normally teeming with people--were silent by afternoon.

At the World Trade Center East, located downtown, most companies sent employees home. According to Barbara Smith-Bacon, senior vice president for Pembroke Real Estate, which developed the building with the Drew Co., the building is open for business today. The company is in the process of developing World Trade Center West, which is currently 70% pre-leased. Both buildings are significantly smaller than the ones in New York, with 16 stories each and about 2,000 employees, but Smith-Bacon tells GlobeSt.com that there are "heightened security measures" around the buildings.

There was an emergency dismissal of 55,000 non-essential state workers, which prompted the MBTA to expand its midmorning service. Tolls on the Massachusetts Turnpike were suspended to help ease the flow of traffic out of the city. Eventually, other transportation centers were closed down, including the Amtrak train depot at South Station. Greyhound shut down its bus service.