PHILADELPHIA (CBS) — One woman is dead and her sister is fighting for her life following a double stabbing in Brewerytown. A relative says the fight started from an Instagram post.

Police say a 19-year-old woman stabbed the two women at 29th and Jefferson Streets, around 11:30 p.m. on Monday.

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They say 23-year-old Shawntae Garrison died after she was stabbed several times in her chest back and legs, just blocks away from where she lived.

Her older sister, 28-year-old Tayshawn Layton, was also stabbed multiple times. She’s currently in the ICU at Temple University Hospital.

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The victims’ grandmother was just a few yards away, sleeping inside her home, when the stabbing happened.

“They had that much nerve to come down here in front of my door and do what they were doing,” Georgia Smith said.

A business owner captured video of a large crowd gathering at 29th and Jefferson Streets. Homicide investigators want to talk with the people seen fighting.

Police are investigating if this fight led to the confrontation that killed Garrison.

Her cousin, Judith Smith, described her as a loving mother of two young children.

“She was a likable girl. She carried herself beautifully,” Smith said. “She took care of her children.”

Police are still working to confirm if the fight started from social media, but a relative tells CBS3 it started from a post on Instagram after a person from one group insulted a person from another group of females.

“We are getting some preliminary information that this is a fight that started over social media, but we don’t have the specifics at this time,” Philadelphia Police Chief Inspector Scott Small said.

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Police say the killer lives near the corner where the stabbing happened. Police add they may also be looking for a second suspect.

CBS3’s Chantee Lans contributed to this report.