WTAE reports the attacker, who has not yet been identified, entered the store at around 5:30 p.m. and headed towards the lavatory. The man was followed into the restroom by two others, but he chased them back out with a knife.
"I took a peek at the top of the steps, and the guy was chasing the dude around with a long, long knife," a witness told Channel 4 Action News. "It was a long, long knife. He was chasing him around through the aisles."
The suspect then ran towards the cash register, grabbed 16-year-old Allison Meadows, and began to stab her.
"He had this girl by the top of her hair. He just kept screaming, 'I'll stab her again.' He kept stabbing her," the witness said.
According to the witness, he and four other men ran toward the stabber and tackled him. He used a baseball bat to keep the assailant subdued until police arrived.
"That little girl, he just kept stabbing her. I just couldn't stand there and watch that," he said. "It was crazy in there. That was horrible. That was something you don't want to see again, ever."
When police arrived, they took the man to UPMC Mercy Hospital to be treated for pepper spray exposure. The teenager was taken to the Children's Hospital of Pittsburgh wits cuts in her back and arm. The two men who where stabbed -- one in the lip and another in the fingers-- were taken to UPMC Presbyterian.
None of the injuries appear to be life threatening, according to police.
Investigators seem to think the incident arose from an assault at a construction site in a near-by neighborhood, after the two injured men followed the suspect into Target. Formal charges are pending.