By Suzanne Le Mignot and Jermont Terry

CHICAGO (CBS) — Simeon Career Academy High School is mourning the shooting deaths of two students, both 15-year-old boys, who were killed in separate attacks just four hours apart on Tuesday.

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Jamari Williams, a sophomore, was killed in a shooting just blocks away from school Tuesday afternoon. Four hours later, freshman Kentrell McNeal was killed in a shooting in Hyde Park that also left a 14-year-old boy in critical condition.

Right after dismissal Tuesday around 2:40 p.m., about 20 to 30 students from Simeon went to Chatham Market, 8301 S. Holland Rd., where they apparently come after school often. The market is located a few blocks away from Simeon.

Outside the shopping center, someone in a black vehicle pulled up and shot Jamari in the chest. A total of at least 13 shots were heard. It was not clear what prompted the shooting.

“It was about 13 to 15 shots,” said witness Johnny Williamson. “It was around the time when the school had let out, so, you know, you heard all the children running and screaming.”

Jamari was taken to University of Chicago Medical Center in critical condition, and was later pronounced dead, according to police and the Cook County Medical Examiner’s office.

CBS 2’s Jermont Terry confirmed the boy was a sophomore at Simeon, located at 8147 S. Vincennes Ave. Jamari’s father also was killed in a shooting in Chicago earlier this year.

About four hours after the shooting that killed Jamari, Kentrell and a 14-year-old boy were shot and wounded outside a McDonald’s at 52nd Street and Lake Park Avenue in Hyde Park.

Kentrell was shot in the head, and taken to the hospital, where he was pronounced dead Wednesday at 9:33 a.m., according to the Cook County Medical Examiner’s office.

The younger boy was in critical condition at Comer Children’s Hospital.

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A source said Kentrell was in his freshman year at Simeon.

Friends held a vigil Wednesday afternoon at a church gym in the Washington Park neighborhood, where Kentrell practiced basketball every Wednesday and Friday as part of the Geek Squad basketball team, an amateur league that travels around the United States and plays different teams.

McNeal was part of Carlil Pittman’s GoodKids MadCity Englewood program. The organization uses basketball as an outlet to help young men learn life skills.

After learning of Jamari’s death, but before Kentrell died, one Simeon classmate said it was just disheartening to hear that another classmate has lost his life.

“We lose a student every year, and it’s like, when is it going to stop? Because we all know when I graduate, it’s not going to stop. We’re going to hear about it again and again and again – and it’s tiring,” said Aie’Rianna Williams, who is not related to Jamari. “Just stop. Like, just stop.”

She pointed out that it is just four weeks into the school year.

“We’re children. Some of us haven’t even hit 18 yet, and we have to lose so many people,” Aie’Rianna said.

Chicago Public Schools says in a statement they are devastated to see the loss of young life and extend their condolences to the family and friends impacted.

Area Two detectives were investigating the shooting near Simeon and were reviewing surveillance video from the shopping center.

Area One detectives were investigating the shooting in Hyde Park.

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No one was in custody for either shooting.

CBS 2 Chicago Staff