“There was a gas leak and explosion at the Upper School,” Minnehaha Academy confirmed. “Emergency responders are on the scene. This only affects the Upper School. If you need to pick up a person from the school, pick up on Edmond Blvd. We will keep you informed as we learn more.”
http://www.fox9.com/news/271498928-story
A planned gas leak attack is or could be a good why to conduct a terrorist attack.
Not saying it was an attack but would be a good cover story.