Just moments before 17-year-old Isaiah Dennis Anderson was shot and killed, he and an old school friend had just said hello and exchanged a hug. It was moments before Monday evening's triple shooting in the 700 block of East Warrington Avenue in Pittsburgh's Allentown neighborhood. The friend went inside her home with her family, then Anderson was suddenly gunned down outside."I live right upstairs. We heard more than 20 shots go off. I've got a baby in the house, so we all got down and looked out the window. We saw him laying right here. My mom was trying to scream, telling him to breathe and all that but he was just gasping for air," Shayla Schmuck told Pittsburgh's Action News 4. "And I knew him, I went to school with him. We weren't really good friends but we were friends, we had quite a few conversations. I literally sat here and watched him take his last couple breaths." Anderson had been a student at Pittsburgh Carrick High School and then at the Pittsburgh Student Achievement Center. Both schools were on modified lockdown Tuesday.Authorities have provided no update on the conditions of the surviving two people shot. The man was in critical but stable condition, shot in the upper body. The woman was grazed in the leg.Anderson's mother, Monica Reifman, released a statement on her son's death saying, "Our son was a loving young man. He filled a room with joy, humor and love. He loved his family and was excited for his next step in life as he was set to graduate high school next month. He was an honor roll student and a community volunteer serving the local football team and at his church. He was a hard worker and I hope that all of you remember that he was so much more than what happened to him. He was a wonderful son, brother, nephew, grandson, cousin and friend. We hope that anyone who knows something is brave enough to come forward. Please cooperate and don’t retaliate."Shayla Schmuck's mother, Victoria Schmuck, was with her daughter and granddaughter when it happened."When I finally stopped hearing the gunshots, I allowed everyone to look out the window and we saw a dude laying right here and he was gasping for air. We were calling 911 already and I was hollering down here, telling him to breathe, to hang in there, the ambulance is coming, they're on the way. He didn't make it," Victoria Schmuck said. "There's just so much senseless violence these days, it's just unreal anymore. It doesn't even matter what it's over. That was somebody's son."Detectives from the Pittsburgh police violent crime unit are investigating.Some people in the community point to the property in front of which the shooting happened. Police are not singling it out."We have a nice little business district there. The problem is this one property. Both of the shootings where teenagers have died in the last year were at the same property," Judy Hackel, vice president of Allentown Community Development Corporation told Pittsburgh's Action News 4.Cmdr. John Fisher of Pittsburgh Police Zone 3 said, "I can't really pinpoint any particular location up there that would be contributing to an increase in violence."