A stairwell at Montclair High School was closed on Wednesday and Thursday for repairs, after some terrazzo tiles had come loose on one of the stairwells.

The damage was cosmetic in nature, not structural, school officials said.

The stairwell, identified as Stairwell 12, is located in the 1956 section of the school, adjacent to the doors leading to the school’s amphitheater.

MHS Principal Anthony Grosso sent a preliminary letter to parents and families on Oct. 30, alerting them that the stairwell had been closed. The terrazzo had come loose from the nosing - the edge of a stair step that most commonly comes in contact with foot traffic - of an individual stair.

The Montclair Fire Department and the district’s architects were called in to do an examination of the stairs, while the Montclair Police Department worked with the school administration and security staff to re-route egress out of the school.

Engineers and architects determined that the stairwell had not sustained any structural damage. “The detachment of the terrazzo was cosmetic damage that posed a tripping hazard,” Grosso wrote in a subsequent letter.

Grosso said the area will re-open on Thursday with access from the ground floor to the first floor, but access from the first floor to the second floor will remain closed while the stairs are being repaired.