CHICAGO — Chicago’s water department commission has resigned in the wake of reports he was under investigation into alleged racist and sexist email messages.

A spokesman for Mayor Rahm Emanuel on Friday cited the probe by the city’s inspector general for the departure of Barrett Murphy.

Adam Collins says Emanuel “acted quickly and decisively” in asking for Murphy’s resignation after learning of the probe into the water department’s culture.

A mid-level Water Department manager, Paul Hansen, has also resigned. Agency spokesman Gary Litherland says he did not know the reason for Hansen’s departure.

Randy Connor, who had been at the Chicago Department of Transportation, will replace Murphy, who rose to the $170,000 a year post last year.