Montville - The owners of Oakdale Plaza are suing the town and the Southeastern Connecticut Water Authority, claiming both were negligent and failed to provide a sufficient water supply to fight a 2010 fire that destroyed the plaza.

In a lawsuit filed last week, John and Kimberly Diamantini say that fire hydrants near the plaza did not have adequate water pressure to fight fires.

The fire, which destroyed the Chapel Hill Road Plaza and displaced eight businesses, was later ruled arson after a fuel-type accelerant was found at the scene, Montville police Detective David Radford has said. The case remains under investigation, Fire Marshal Raymond Occhialini said Friday.

The plaza was uninsured, and John Diamantini estimated at the time that there was $1 million in damages to the structure and businesses. Many of the businesses that were displaced, including Oakdale Pizza, have reopened in a new shopping center on Old Colchester Road.

Gordon Videll, an attorney with the law firm representing the Diamantinis, declined comment Friday. Mayor Ronald K. McDaniel Jr. also declined comment on the litigation, as did Water Authority General Manager Gregory Leonard. The water authority serves about 10,000 people in Ledyard, Montville, North Stonington and Stonington.

The lawsuit says the town and water authority were responsible for furnishing an adequate water supply for fighting fires. The suit claims the Diamantinis were led to believe that fire hydrants in the area were suitable for fighting a potential fire.

Residents at a municipal water commission meeting in 2010 also questioned why the fire hydrants near the property were not used to fight the blaze. They were told by a water authority official that the hydrants, which date to the 1950s, were not designed as a primary firefighting tool. Rather, officials said, the hydrants were designed to flush and clean the drinking-water system.

The lawsuit also said the water authority should have been aware of the dangers of a potential fire because of another fire that took place a month before the Oakdale Plaza blaze. The lawsuit argues that the plaza has lost value because potential renters are aware of the inadequate fire hydrants in the area.

The Diamantinis in April 2011 filed notice of their intent to sue the town. They are seeking monetary and compensatory damages.

jeff.johnson@theday.com