Two men were killed in separate overnight shootings on Chicago’s South Side, according to the Chicago Police Department. In Grand Crossing, a 66-year-old man was struck and fatally wounded in a drive-by attack. Police said the shooting occurred late Tuesday but released no further details on the circumstances or possible motive. Roughly an hour later and 10 miles southwest in West Pullman, officers responding to reports of gunfire found a man believed to be between 20 and 25 years old with a gunshot wound to the head inside a vehicle on the 12000 block of South Lasalle Street. Investigators said a dark-colored sedan pulled alongside the victim’s car and someone inside opened fire. The man was taken to Advocate Christ Medical Center in Oak Lawn, where he was pronounced dead. No arrests have been made in either case, and detectives are investigating whether the incidents are connected.