Visitors to the United States' tallest building can again ride an elevator to the top. The observation deck on the 103rd floor of the Sears Tower in Chicago is open for the first time since the September 11 terrorist attacks.

The Sears Tower Skydeck is one of Chicago's top tourist attractions. It draws about 1.3 million visitors a year who, on a clear day, can see four U.S. states. The skydeck never opened the morning of September 11, and has been closed for a security review ever since.

Monday morning, Chicago Mayor Richard Daley was among those on hand for the re-opening. "It was prudent to close the Sears Skydeck as a precautionary measure following the attacks at the World Trade Center," he said. "Now it is time to get things back to normal here and throughout the nation."

Former President George Bush Sr. was also at the re-opening, calling it a proud moment for Chicagoans, and all Americans. "By reopening this symbol of strength and vitality in America's heartland," he said, "you are sending a message that the terrorists have failed in one of their objectives."

During the past seven weeks, two security consulting firms have studied the skydeck and other areas of the Sears Tower, and have recommended ways to make the building safer for workers and visitors. Steve Budorick, a vice president for TrizecHahn, which manages the Sears Tower, says visitors will now have to pass through metal detectors. Their bags and packages will be run through an airport-style x-ray machine.

Mr. Budorick said, "Certainly it is disappointing that we have to do that, but if it makes our tenants and customers feel better, then we stand ready to do make that happen. We have to respond to our customer base, and the important thing is their safety and security and comfort."

Other apparent security changes to the Sears Tower include concrete barriers surrounding the building. Workers have to show identification before being allowed onto elevators. About 10,000 people work in or visit the Sears Tower every day.