Preston — A lot has changed at the former Norwich Hospital property since October 2012, the last time the Preston Redevelopment Agency hosted a bus tour of the main campus behind the security fence.

With 46 structures now demolished and work started to remediate some of the largest buildings at the former state mental illness hospital, the PRA will once again invite residents, business owners and potential developers to see the progress of the cleanup.

PRA officials will lead guided tours aboard two school buses on Saturday, June 7, beginning at 9:30 a.m. Participants will gather beneath a tent at the Route 12 campus to view display boards showing aerial photographs showing "before" demolition and "after" views the property and graphics of development parcels.

Buses will load at 10 a.m. for driving tours of the main campus on the west side of Route 12. PRA member Michael Clancy said about 30 adults can fit on a bus. Tours will last about 40 minutes. If necessary, additional bus runs can be made, Clancy said.

"The whole site is going to look completely different than the last time," Clancy said.

PRA Chairman Sean Nugent said PRA officials recently attended a retailers' conference in Hartford and displayed aerial photos of the former hospital campus, now called Preston Riverwalk, taken in 2008 - one year before the town took ownership of the property - and another taken in 2013 for comparison,

More demolition progress has been made since that photo and Nugent said he will draw white X marks over the buildings that are now gone.

"What we're really trying to demonstrate now is that 46 buildings have been demolished," Nugent said. "The newer buildings are being wrapped because we're doing the abatement on them. We want to give people a sense of where we are and where we're going."

No registration is necessary for the tours. For more information, contact Clancy at (860) 886-0795 or email mclancy@prestonriverwalk.com.

c.bessette@theday.com