ABC says 20 injured after the incident took place, Jezebel has some coverage here. The stabber is reportedly a male sophomore and is in custody. Some of the victims may have life-threatening wounds. Via ABC:
At least 20 people were injured after a stabbing spree inside Franklin Regional High School in Murrysville, Pa., at the start of the school day, emergency management officials said.
Westmoreland County emergency management spokesman Dan Stevens said no fatalities were reported.
At least four people with injuries Stevens described as “serious” were flown to area hospitals for treatment. He said some of the injured suffered stab wounds to the extremities.
Others were not actually stabbed, he said, and some of their injuries were cuts and scrapes.
The breakdown of injured and whether they were students or staff was not immediately known, but two hospitals reported nine patients ranging in age from 15 to 60.
Alyssa Finch, who said she is a student at Franklin Regional High School, told ABC News a fellow student pulled the fire alarm during the stabbing “because he knew what was happening … and he wanted the people to get out.”