Due to the overwhelming popularity and close-out of this Sunday’s Sept. 21st Walking Tour entitled “Union Square: An Intermixing of Industry, Immigration and Innovation,” the Somerville Historic Preservation Commission expects to repeat the tour the following Sunday, Sept. 28.

Again it will be a free event co-sponsored with ArtsUnion. It will start at Somerville High School (91 Highland Ave.) at 2pm and end at 4:30pm. The route will include interior visits to the historic St. Anthony’s Church on Properzi Way and the new Greentown Labs off Dane St. There is no rain date if heavy rain or wind prevails. Prior registration is again required by contacting Brandon Wilson via bwilson@somervillema.govor 617-625-6600, ext. 2532.