The New York Post said Simmons, a mosque supporter, posted religious and spiritual symbols spelling out the word "coexist" on the windows of his apartment across from Ground Zero.
"This is compelling for Russell because he lives here and he's always involved with issues of people getting along," his friend Glen Friedman, who designed the lettering on the windows, told the newspaper.
The mosque is to be part of a proposed $100 million Islamic cultural center to be built on private property two blocks from where the World Trade Center was destroyed and more than 2,000 people killed by Islamic extremist terrorists on Sept. 11, 2001.
There has been much debate between those who feel building an Islamic place of worship so close to the site is disrespectful to the memories of those who perished there, and those who think its presence represents freedom of religion and will help the healing process.
Celebrity Families of 2014 [PHOTOS]