A small memorial that's been hosting tours led by volunteers with personal ties to the Sept. 11 attacks is moving and expanding.

The privately-funded Sept. 11 Tribute Center is currently housed on the site of a former deli that was just feet from one of the collapsed towers. By spring 2017, the center plans to reopen a few blocks away in a 40,000-square-foot space.

Years before the National September 11 Memorial & Museum opened, artifacts from the attack and recorded memories were kept at the Tribute Center.

About 800 volunteer guides now take visitors on walking tours of the 9/11 site. Some are survivors, others first responders, victims' family members and neighborhood residents.