CHICAGO (CBS) — Police were searching for clues in the deaths of twin brothers who were gunned down in the Old Town neighborhood early Sunday, and a $2,000 reward has been offered to find the killer.

Edward and Edwin Bryant, both 17, were visiting their old neighborhood when someone in a passing dark-colored vehicle opened fire around 3 a.m. Sunday at the corner of Hudson and Evergreen avenues.

Both brothers were taken to Northwestern Memorial Hospital, where they were pronounced dead about an hour apart from each other. Edwin had been shot in the chest and back; Edward had been shot in the chest and head.

Tio Hardiman, president of Violence Interrupters Inc., said he’s known the Bryant family for years.

“They used to live in the neighborhood, okay? They was over there visiting family members, and then they were walking a friend home, and then they were going to leave, and after they walked the friend home, I guess some people outside were waiting or looking,” Hardiman said.

The fraternal twin brothers were athletes; Edward played basketball, while Edwin played football.

“It’s tough. It’s tough when an older person passes away. It’s even tougher when a kid passes away from something that nobody can seemingly explain,” said Vince Carter, director of the Chicago Demons Basketball program. “I have a twin brother and sister – they’re not my twins, but my brother and sister, they’re twins – and so it’s just ironic that two kids would be born on the same day and then they die on the same day.”

Hardiman said Edward was being recruited by several colleges to play basketball.

The boys were juniors at Marshall Metropolitan High School in East Garfield Park. Classmates were stunned by the news of their deaths.

“They don’t be getting in trouble. They’re cool with everybody, so that’s probably it was a surprise to everybody,” Dashiera Butts said.

Chicago Police Supt. Eddie Johnson said the shooting appeared to be gang-related. Johnson said the brothers were not in a gang, but the people they were standing with are documented gang members.

“The two brothers, as far as we can tell, they didn’t have any documented gang affiliation, but the individuals they were with did. So it’s possibly gang-related,” he said.

No one was in custody Monday morning. Area North detectives were investigating.

Johnson said detectives have been making progress in the case, and have video of the shooting.