CHICAGO (CBS) – A look back at the September 11th attacks includes a look up in Chicago to the Willis Tower. The Chicago icon was among those eventually named as a potential terror target.

As CBS 2’s Vince Gerasole reports, in the decade since 9/11, the building has experienced its own ups and downs and is currently rebounding.

The Willis Tower’s place as the tallest building in the western hemisphere also made it a named terror target; and the impact of that can sometimes linger.

South Side resident Robin Brooks, who works at the Willis Tower, said she realizes her workplace is a likely terrorist target, but she’s not worried.

“Working here, it does go through my mind, but I feel really safe being here in the Sears Tower. The security is tight,” she said.

In the days immediately after the attacks, what was then the Sears Tower sometimes looked like an imposing, with guarded reinforced entrances.

Now, more advanced and efficient security systems have a softer look as 10,000 people a day pass through the building.

“We’ve attracted more locals coming through here than we’ve ever done before,” said Randy Stancik, a vice president at U.S. Equities and general manager of Willis Tower’s Skydeck.

Visitors are now captivated by Willis Tower’s “Ledge” – four glass window boxes on the building’s 103rd floor Skydeck that extend from the outer wall of the skyscraper.

Attendance should hit 1.4 million this year, after a drop following the 9/11 attacks.

Leased office space that fell by 20 percent after 9/11 is also on the rebound. Last year, 93 percent of the building was spoken for.

“The big thing we needed to do is really take a step back and think about moving forward,” Stancik said. “We’ve got to make sure that access is – number one – safe and – number two – very fluid for our visitors and people who work here in the building.”

Major new tenants like United Airlines have also benefitted from aggressive pricing.

Two years ago, Peter John, a partner of the law firm Williams Montgomery & John, jumped at the chance to move the firm to the Willis Tower.

Asked if he ever thought of terrorism when considering the move, John said, “I think some people did, initially, when we announced we were going to do it. But nobody said we are not going to come because of it. So, obviously, the concern about terrorism had diminished greatly.”

Those fading concerns have public again seeing the Willis Tower as it was seen before 9/11.