You will remember that last year I was attacked in my classroom for taking away a student's cell phone for texting in class, after being ordered to do so by the principal of the school.
My wife, who teaches at an entirely different school, was also recently attacked by a student. The incident was the culmination of a series of events over a three day period:
1 The student entered class while chewing gum, and was told to throw it away. The student displayed an attitude, and an argument ensued. Rather than write a formal discipline referral, my wife asked administrators to have an informal talk with the student.
2 The next day, the student AGAIN entered the class chewing gum. After being told to spit it out, she claimed that she "forgot" about the no gum rule.
3 The next day, the student came in wearing a hoodie with the hood up. When she was told that this was against the school's uniform policy, the student argued and called my wife, her teacher, a "fucking bitch."
My wife wrote her a discipline referral. After leaving the office from receiving her suspension, she immediately walked down the hall to my wife's classroom and attempted to physically attack her. The only thing that prevented the completion of the attack was the vice-principal, the school's police officer, and the superintendent of the school were next door for a meeting. They locked my wife and her students in their classroom for safety, and immediately escorted the student off campus with a trespass warning not to return.
Less than an hour later, the student and her mother called my wife in her classroom, threatened her, and stated that she was a "races" or something. My wife was so concerned that they were going to be waiting for her after school, coupled with the fact that she is disarmed by law, that she had the school's police officer escort her to her car.
I would say that we would be extra vigilant over the next few days, but I honestly cannot think of any precautions we could be taking that we already don't: We have a burglar alarm, security/landscape lighting (both visible and infrared), and security cameras, and we are armed everywhere that we legally can be.