Police arrived at the scene of the shooting around 12:46 a.m. in the 1900 block of Missouri Street and found 10 people with gunshot wounds, three of them unresponsive, according to officials.
Three people were pronounced dead at the scene: A 27-year-old man from Lafayette, Indiana; a 20-year-old woman from Olympia Fields, Illinois; and a 25-year-old man from Merrillville, Indiana.
The other gunshot victims were taken to local hospitals by ambulance and as well as personal cars, police said. Their conditions are unknown.
Gary police are investigating. Anyone with information on the shooting is asked to call the Metro Homicide Unit at 219-755-3855 or the Crime Tip Line at 866-CRIME-GP.