Police say a 16-year-old girl poured gasoline on two Pennsylvania high school security guards and unsuccessfully tried to ignite it using a grill lighter.
Wilkinsburg student Imani Knight-Brantley is in jail after being charged as an adult.
Police say the girl told them she returned to school angry on Monday because of an earlier confrontation with one of the guards. They say the teen says the guard called her names and put her in a headlock Friday.
Online court records don't list an attorney for the girl. She was arraigned Tuesday on charges including aggravated assault and risking a catastrophe.
The company that provides the guards didn't immediately return a call for comment.
A school spokesman says the guard was working Tuesday but likely won't return Wednesday while officials assess the situation.
Students at the seventh- through 12th-grade school in Pittsburgh's eastern suburbs were initially evacuated to a nearby community center, then dismissed so their parents and guardians could take them home.
The impoverished school district last week announced a plan to close Wilkinsburg's secondary school because of declining enrollment. Under the plan, 200 or so Wilkinsburg students will be sent to an underperforming Pittsburgh school next school year, Pittsburgh Westinghouse Academy, which has roughly 400 sixth- through 12th-grade students.
Both school boards must still approve the plan.