Walmart on Tuesday filed a lawsuit against Tesla's solar-energy unit in New York state.

The retail giant alleges solar panels installed by Tesla caught fire at seven stores

Shares of Tesla fell more than 2% in overnight trading on after the lawsuit was filed . Follow the stock in real-time here.

. Follow the stock in real-time here. Tesla did not respond to a request for comment from Business Insider.

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Walmart on Tuesday filed a lawsuit against Tesla, accusing the company's solar-energy subsidiary of gross negligence after multiple stores experienced fires they say stemmed from solar panels on their roofs.

"As of November 2018, no fewer than seven Walmart stores had experienced fires due to Tesla's solar system," the company said in its lawsuit, filed in New York state court.

Inspectors look at damage from a fire at a store in Indio, California. Court filings Walmart alleges the incidents were linked and that they were all a result of "widespread negligence" on behalf of Tesla and its employees, who installed the systems on more than 200 stories, which are now all laying idle.

"Tesla has also demonstrated an inability or unwillingness to remediate the dangerous conditions documented in its inspection reports," the complaint says.

Tesla did not respond to a request for comment from Business Insider.

Shares of Tesla fell more than 2% overnight ahead of Wednesday's opening bell after the lawsuit was filed.

Walmart said in the complaint filing that it has leased or licensed roof space at more than 240 stores for Tesla-supplied solar-energy systems.

"Walmart's consultants accompanied Tesla personnel on inspections of various solar system sites, including both those that had experienced fires and those that had not," the complaint reads. "These visits revealed that Tesla had engaged in widespread, systemic negligence and had failed to abide by prudent industry practices in installing, operating, and maintaining its solar systems---conduct that greatly increased the risk of fire at Walmart sites."

Local news showed a fire at a Beavercreek, Ohio, Walmart in March 2018. WHIO

Before it was acquired by Tesla in 2016, SolarCity inked deals with Walmart as early as 2010 for solar projects. According to company press releases, the company had already completed more than 200 solar projects at stores by 2014.

The lawsuit filed on Tuesday is far from the first that Tesla has faced regarding SolarCity since the acquisition. In 2018, three former employees alleged various types of misconduct at the company, including accusations that SolarCity employees falsified sales accounts in order to inflate their bonuses, along with the value of the company as a whole.

The suit also alleged discrimination, harassment, and inadequate pay. A Tesla representative told Business Insider when the suit was filed that Tesla had investigated the allegations and found them to be untrue. The suit has since moved to private arbitration.

In recent months, Tesla has begun to ramp up its solar-energy unit after reporting the lowest number of quarterly installations to date in the second quarter. The company said on Monday it would offer solar-panel rentals for as low as $50 per month in some US states, with plans to offer a similar product in Europe soon.

Read more: Some Tesla customers who ordered the Solar Roof have no idea when they'll get it

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Read the full complaint: