The largest remaining artifacts from the Sept. 11, 2001, terrorist attacks were removed from a hangar at Kennedy Airport on Tuesday as the building is prepared for aviation use again.

A 40,000-pound parking-structure column, a 35,000-pound elevator motor and a 40,000-pound antenna connector were received by the Tunnel To Towers Foundation, an organization that has created traveling exhibits of 9/11 memorabilia, according to The Wall Street Journal.

The hangar is being cleared out of 2,500 artifacts taken from Ground Zero.

“It’s important for our country not to forget what happened on that day,” said Frank Siller, head of Tunnel To Towers.