Philadelphia police investigators are searching for leads in a shooting that left a 14-year-old boy dead in the Mayfair section Monday night.

Ian Wilsey, a ninth-grader at Northeast High School, and a 16-year-old friend were hanging out in the Northeast Philadelphia neighborhood around 9 p.m., when they decided to walk to a nearby store for a snack.

Two men ambushed the teenagers, authorities said. When they tried to run, the suspects opened fire with a semiautomatic handgun. Wilsey was struck in the chest three times. One of the bullets pierced his heart. 

"They just started shooting," Wilsey's friend, who has asked to remain anonymous, told 6ABC. "They didn't say anything. They didn't stop to talk to us. They just started shooting."

Wilsey was taken to Aria Jefferson Health Torresdale hospital, where he died a short time later. 

Neighbors were shaken by the shooting, which took place on the 6200 block of Brous Avenue, just blocks north of Frankford Avenue. 

Patricia James, 67, who lives nearby on Devereaux Avenue, told the Philadelphia Inquirer that she was in bed when she heard gunfire and saw flashes.

A GoFundMe page was created to help Wilsey's family pay for funeral costs. The website has also served as a place where people can pay tribute to the boy, who would have turned 15 in December.

"Ian left a lasting impression on me after having him last year. Some days tough, but mostly fun. I loved our Monday morning conversations about football," Wilsey's former teacher, Jessica Nicholls, wrote. "He will be missed. Cherish all the wonderful memories of him."

Detectives have little information about the two suspects and any possible motive in the attack.

"We don't know if it's a robbery [or] a prior altercation," Philadelphia Police Homicide Capt. James Clark said. 

Detectives are searching for any witnesses and reviewing surveillance footage. They believe the two men exited a car and ran off. One suspect was described as wearing a dark, hooded sweatshirt, and the other was wearing a "very small beanie hat," PPD Chief Inspector Scott Small said. 

The PPD is offering a $20,000 reward for information that leads to the arrest and conviction of anyone involved. Police urge anyone with information to call the homicide unit at 215-686-3334.