CHICAGO – Chicago city officials joined firefighters in a moment of silence Wednesday to commemorate the 23rd anniversary of the September 11 attacks.

On that day in 2001, terrorists hijacked four jetliners, crashing two into the Twin Towers, one into the Pentagon, and a fourth crashed into a Pennsylvania field after passengers fought off the hijackers. Nearly 3,000 people were killed in the attacks, including 343 emergency workers.

In Naperville, community members will gather tonight to pause and remember the lives lost. The city’s memorial was one of the first in the country to be erected after the attacks, inspired by Naperville-born U.S. Navy Commander Dan Shanower. Shanower was working at the Pentagon on Sept. 11, 2001 when he was killed.

Shanower, a graduate of Naperville Central High School, aspired to a career in the Navy. His words, “Freedom ain’t free,” written in an article, inspired the monument.

The memorial, located between the DuPage River and the Naperville Municipal Building, features a steel beam from the World Trade Center, fragments of the Pentagon and granite from Pennsylvania Field, where Flight 93 crashed after passengers thwarted an attack on the U.S. Capitol.

Tonight Naperville will honor the victims with a ceremony beginning at 6 p.m.

“It really hits you when you have that connection to the community,” said Naperville Mayor Scott Wehrli. “We never forget it in Naperville, and tonight this entire riverwalk is going to be filled with hundreds of people who are going to be here to watch the ceremony and say their prayers.”

The memorial also features a 48-foot-long wall of faces, which represent the victims of the attacks. The public is welcome to attend tonight’s ceremony and pay their respects.