SEATTLE – Police are trying to find out who pulled shot and killed a teenage boy and injured a girl Thursday night at a private party in Seattle. 

Allen Joplin, 17, died at the scene.  A 13-year-old girl was also shot in the leg and is being treated at Harborview Medical Center for life-threatening injuries.

Annette Brown is trying to absorb the awful truth that she'll have to bury her baby brother.

"I feel selfish. Why my brother right now? Why him?" asks Brown.

Everlena Joplin raised her great grandson since he was three weeks old.

"I'm just hurt.  Whenever I think about it, all I can say is my baby's gone. That's all I can say," said Joplin.

Allen's family is wondering if the former Cleveland High School football player was targeted, partly because of something that happened Thursday night before he left their south Seattle home.

"He didn't tell me where he was going last night but he got in a big argument with somebody on the phone.  I said 'Allen, you had a big argument on the phone.  I don't appreciate you going out tonight because somebody might try to hurt you,'" said Joplin.

KING

Allen Joplin

Police say more than 100 teenagers, mostly students from Franklin and Cleveland high schools, were attending the invitation-only dance party at a rental space called Studio 116 on Elliott Ave. W. in the lower Queen Anne neighborhood.

Police say the party was in full swing when uninvited guests crashed the event shortly before midnight. After words were exchanged between the uninvited guests and partygoers at the door, the suspects went inside the building and opened fire.

"Words were exchanged, shots were fired," said spokesman Mark Jamieson, Seattle Police Dept.

Witnesses described what they saw.

"She told me she heard four shots and then she ran and then she went back in to get her friends coat and she saw Allen coughing up blood and stuff," said one teen.

It took several hours for police to interview all the witnesses. Witnesses reported seeing two men run from the scene after the shots were fired. Some also said they saw the suspects drive off in a large vehicle, possible a Lincoln, 1990s model, dark blue with tinted windows.

Jamieson says gang involvement is suspected and two individuals are being sought in the shooting.

Joplin's family says he was drawn to sports at an early age, but also hung out with some questionable friends who worried his great grandmother and sister.

"I just with I could have been in his life more.  I'm not gonna blame myself. The lord's will is the lord's will, but at the same time I just wish there was something I could do," said Brown.

Security at Studio 116

The party was back to school bash following the winter break, planned by a group of high school girls.  The owner of the space tells KING 5 he rented it to the children's' parents.  He didn't anticipate 130 teenagers would show up.

Security cameras at an espresso shop next door picked up the chaos after the shootings.  The owner of Espresso Elegance has concerns about security at the rental hall.

"I believe they hire someone to watch the place when there are parties. I've never seen true security like as far as a police officer or a professional security guard," said Terry Patton.

Studio 116 is a photography studio by day and rented out for parties at night. 

There is a question about how many adults supervised the party.

"There were at least two adults.  The gentleman who owns the space has a relative who was there with his girlfriend," said Seattle Police spokesperson Renee Witt.

The Studio 116 owner says this is the first time in eight years that there's been a problem after renting out the space.