Authorities are investigating the shooting deaths of five people in a single day of bloodshed in Chicago.

Police Officer Daniel O’Brien says Saturday’s first killing occurred at around 2:15 a.m. on the city’s west side when a gunman opened fire on two men who were sitting in a parked car, killing one and wounding the other.

Investigators say a few hours later, someone opened fire on three men near a South Side eatery, killing two of them and wounding the third.

Detectives were called to the scene of another shooting Saturday afternoon in which a man in his 30s and a teenager were shot to death. There had been no arrests.

Chicago’s homicide count eclipsed 500 last year for the first time since 2008.