Simon Gratz High School reopened Thursday after asbestos forced its closure

Simon Gratz High School in Strawberry Mansion reopened to students on Thursday, after it abruptly closed due to asbestos

In a letter to families, Mastery Charter Schools CEO Scott Gordon said "all findings that needed to be remediated in order for the school to reopen are now complete" and added that air quality samples came back negative for asbestos. 

Officials closed the school over a week ago when inspectors from the School District of Philadelphia found damaged asbestos on the campus of Simon Gratz High School, which also houses Simon Gratz Preparatory Middle School. 

Officials say the three-year reinspection of the district-owned building was in accordance with the Asbestos Hazard Emergency Response Act. The district recommended the school be closed for the duration of the inspection, according to school officials.

Simon Gratz Preparatory Middle School reopened earlier this week, but the high school remained closed until officials announced its Thursday reopening. The school's auditorium will remain sealed off as inspectors from the school district complete their inspection that's been more challenging due to the room's high ceilings. 

"Out of an abundance of caution, the District has created a negative pressure environment so that there is no air flowing from the auditorium into the school," Gordon's letter reads. "The work in the auditorium can continue while school is open."

Students who gather in the auditorium at the start of each school day were moved to the cafeteria until classes began at 8:05 a.m.