Masters, along with Jeff Frank, put together the memorial.
He said he hopes the sign also gave strength to those taking part in the Ironman Wisconsin competition.
Other members of the Madison community reflected on 9/11 through music on Sunday afternoon.
The Madison Symphony Orchestra hosted a free concert to commemorate the day with songs honoring those who lost their lives and loved ones.
"Our thoughts to put this concert together was to give the community a voice and a place to commemorate and observe what happened 10 years ago that was so significant to the lives of so many people," said artistic director Gary Lewis. Lewis said around 300 volunteers from the Madison community participated in the concert.
Elsewhere, a University of Wisconsin-Madison student organization planted more than 3,000 American flags on Bascom Hill. The group responsible said its goal is to urge other students to come together and honor the victims.