INDIANAPOLIS (AP) — Dozens of people who were sickened by fumes after a chemical reaction at an Indianapolis public pool a year ago have filed claims against the city, raising the possibility that the accident and ensuing evacuation could cost the city as much as $2 million or more.

Documents show city officials have already settled claims totaling $33,456, WTHR-TV reported Friday. The remaining unsettled claims range from $340 to one family filing three separate claims for $750,000 — a total of $2.2 million.

A spokesman for Indianapolis Mayor Greg Ballard didn’t immediately return a phone call seeking comment Friday.

The claims stem from a chemical reaction that forced an evacuation at Garfield Park pool on June 21, 2012. Seventy people, mostly children, went to hospitals for treatment of symptoms, which included nausea, breathing problems and watery eyes.

A city review found that a park employee didn’t reopen a valve following a routine backwash of the pool, setting off a chain of events that allowed two chemicals to combine into chlorine gas and enter the pool.

“They overmedicated the pool,” Bloomington attorney Ken Nunn said Friday. “They put too many chemicals in the pool.”

It was closed for several days while repairs were made and procedures for handling chemicals were updated.

The city faces four lawsuits, including one filed Wednesday in Marion County court by Nunn, who is representing a 40-year-old woman he said suffered serious lung damage. Nunn said the woman has acquired about $3,000 in medical bills since the accident, and her hair is also falling out. Physicians believe the pool chemicals caused her illness, Nunn said.

An Indiana Occupational Safety and Health Administration inspection found the pool’s circulation system had inadequate flexible tubing that leaked and exposed employees to corrosive chemicals. The report also said the pool didn’t have proper gloves and flushing equipment for workers and had some unsafe electrical outlets.