CHICAGO (WLS) -- Police are conducting a homicide investigation after three men were found dead in a home in the Mayfair neighborhood on Chicago's Northwest Side.The men were found during a well-being check in the 4600-block of North Kostner around 5:25 p.m. Friday, police said. The victims have been identified as Roberto Cervantes, 38; Joel Cervantes, 29; and Jesus Cervantes, 72."They were just a loving family, they were really friendly," said Walter Eliasen, a neighbor.Neighbors said they believe the dead men are two brothers and their father. Neighbors spoke with one of the men moments before the shooting."I yelled out to them and I says, 'Are you coming out to the block party for tomorrow?' And he said 'Yeah,'" Eliasen said."We were chatting about the block party we have coming up tomorrow, kind of getting prepared for it. And all of a sudden bang, bang, bang," said Mike Rufo, a neighbor.It's not clear who pulled the trigger or what exactly happened in those final moments.Police said the shooting was an isolated, domestic incident.