A series of shootings in Colorado Springs has left four people dead and two injured, police said.The mayor of Colorado Springs called it "a sad day" for his city. "The entire community mourns with those who lost loved ones to serious crimes last night," Mayor Steve Bach said at a news conference Thursday. The three bursts of gunfire Wednesday night were unrelated and occurred in different areas of the city, police Sgt. David Edmondson said. The heaviest toll came near Montebello and Mira Loma Circle in central Colorado Springs, leaving three men dead, the officer said in a news release. When police arrived to investigate a report of shots fired, they found two people dead and one wounded, Edmondson said. The injured man later died at a hospital.The dead were identified as Aaron Fix, 16, Wayne Fix, 19 and Austin Howse, 16. Aaron and Wayne were brothers, according to police.The suspect in the slayings was identified by police as 24-year-old Michael Arangio. Police said he is armed and dangerous and should not be approached. Earlier in the evening, one man was killed and another person wounded at an AutoZone store in the eastern part of town. Edmondson said police responded to a report of shots being fired and found a man lying dead in the parking lot and another person wounded inside the store. The gunman remains at large after carjacking a vehicle and taking a man hostage, later releasing him unharmed, police said. In a third shooting on Wednesday night, Edmondson said police officers wounded a 21-year-old man who had a handgun. He said the shooting came after the man fled from police and took refuge in an apartment building.