KLEIN, Texas (KXAN) — On Tuesday, a firework explosion resulted in the evacuation of a Harris County high school.

According to the Harris County Fire Marshal’s Office, the preliminary investigation shows that a firework was ignited inside Klein Forest High School in Klein, Texas. At the time, HCFMO believed that a person may have been injured.

Klein ISD later clarified with updates via Twitter, saying that all students and staff were safe and classes would be dismissed early. It said students would be able to pick up their belongings at a later time.