DALLAS—A federal lawsuit filed by the Justice Department on Tuesday alleges the city of Dallas fired one of its own because he was black.

The lawsuit says Frenchell Willis, who had been a general laborer in the Water Utilities Department, was also retaliated against for reporting discrimination, The Dallas Morning News reported for its Wednesday editions.

The suit alleges that on the same day Willis told senior managers that his immediate supervisors were calling him racial slurs, he was fired.

“The city had non-discriminatory and non-retaliatory reasons for the employment decisions and employment action taken by the city in this case,” said City Attorney Tom Perkins, who said Dallas will “vigorously defend the lawsuit.”

Willis joined the Water Department in October 2006.