Students at one Montgomery County high school will be learning virtually on Wednesday after a threat of violence, according to administrators. A threat against Wissahickon High School has forced the school’s administration to switch to a virtual instruction day on March 26. Superinten dent Dr. James A. Crisfield explained in a note to families that there isn’t any evidence that the threat is credible but an investigation is underway. All of the other Wissahickon School District schools will have in-person classes on March 26. This is a developing story. Check back here for updates. This story uses functionality that may not work in our app. Click here to open the story in your web browser. ...read more read less