By Matt Petrillo

PHILADELPHIA (CBS) – Two men were killed and two others were injured in a quadruple shooting in Philadelphia’s Kensington neighborhood. Investigators say more than a dozen shots were fired from a semiautomatic weapon.

“24th District police responded to numerous 911 calls,” Philadelphia Police Chief Insp. Scott Small said.

Philadelphia police rushed to the 1900 block of East Somerset just after 11 p.m. Sunday, initially finding three men with gunshot wounds.

A 21-year-old man was shot in the leg and a 33-year-old man shot in the back. Both were taken to Temple University Hospital. The 33-year-old victim was pronounced dead shortly after 1 a.m.

A third victim, a 38-year-old man, died before police could get to him.

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“While investigating this scene, we were notified a fourth victim was shot,” Small said.

That victim, a 45-year-old man, was taken to a nearby hospital by someone at the scene. He was also shot in his leg and is in stable condition.

“We found 15 spent shell casings, some on the sidewalk, some on the highway,” Small said. “It appears the shell casings are the same caliber. It appears from a visual inspection.”

Now detectives are combing the neighborhood, looking for any security video that might have captured the gunman and the moments before the gunfire erupted.

“Our crime scene is going to process the scene due to the fact that it is a homicide,” Small said.

For a list of gun violence resources in Philadelphia, click here.