Forty luminaria are placed at the wall of names in memory of the 40 passengers and crew of United Flight 93 at the Flight 93 National Memorial at sunset on Monday, Sept. 10, 2012 in Shanksville, Pa. Tuesday marks the 11th anniversary of the Sept. 11, 2001 terrorist attacks.

SHANKSVILLE — Defense Secretary Leon Panetta visited the Flight 93 National Memorial in Pennsylvania on Monday and called it “the final resting place of American patriots.”

Panetta made his first visit to the site where 40 passengers and crew members died during the terrorist attacks of Sept. 11, 2001. He said he came “to extend our nation's deepest gratitude to the heroes of Flight 93.”

United Flight 93 was traveling from Newark, N.J., to San Francisco when it was hijacked by four terrorists. The 9-11 Commission said the terrorists likely wanted to crash the plane into the White House or the U.S. Capitol, but the jet went down in a field near Shanksville after passengers and crew fought back.

Panetta said the people on the plane “responded with selflessness, determination, and tremendous courage. And at the cost of their own lives, made the fateful decision to fight back, and in so doing, they successfully prevented an attack on the United States Capitol.”

Panetta walked down to the wooded area where the plane crashed and met with relatives of people who were on the plane. The park is in a rural area about 75 miles southeast of Pittsburgh, but some visitors find it so moving they have made repeat visits.

“I've been here in the dead of winter before,” said Sue George of Ridgeley, W.Va., adding that she loves that the names of each of the victims is inscribed on a wall of large, white marble tablets. The wall is aligned with the flight path of the plane. George also noted that the 2,200-acre site, which was once a strip mine, is now filled with beautiful views, hills covered in wildflowers and trees.

“It still feels almost wild. Which I think is the best thing ever,” she said. “It's not a sad place anymore. It's our way of saying 'thank you.”'

More and more people are visiting the memorial, according to the National Park Service, and officials hope to break ground on a visitor center next spring, and complete more tree plantings and walkways. That phase is scheduled to be completed by 2014.

A third phase, which could cost $5 million or more, will include a learning center and a tower at the entrance with 40 wind chimes. Price estimates for the whole project have ranged from $67 million to $76 million.