FLAT ROCK, Mich. (AP) — Authorities told hundreds of people in a Detroit suburb to return home Thursday, ending a three-week voluntary evacuation after gasoline from a Ford Motor factory got into the sewer system.

The leak “is no longer a risk to the indoor air of Flat Rock homes and businesses in Zone 1,” state and local health departments said.

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Zone 1 has about 500 homes. Zone 2, with 635 homes, got the green light Monday in Flat Rock, 25 miles south of Detroit.

Wayne County said the lone exception was a handful of homes that initially had elevated levels of benzene or suspicious odors. Flat Rock’s drinking water system wasn’t affected.

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“I want to thank Flat Rock residents for their resilience throughout this difficult time,” said Genelle Allen, Wayne County chief operating officer.

Ford Motor has been paying to put residents in hotels. The offer will continue for residents who still are awaiting written results from tests.

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