When considering the tort liability of school districts or their employees for injuries suffered by students, the court basically mentions two separate problems: first, whether under the facts of the case any duty of supervision was owed to the injured person; second, whether such duty, if owed, was reasonable and was satisfactorily conducted by the supervisory personnel. These basic statements are enlarged upon in connection with chemistry, shop, and manual or vocational training classes where the supervisory duty of school personnel is generally described as that of a reasonable or prudent person. Therefore, the level of caution or alertness required of the teacher or the employee is commensurate with the degree of danger inherent in the particular situation. The standard of care requires that the school district and its employees anticipate a wide range of dangerous acts and conditions that could expose the student to an unreasonable risk of harm. As a result, the "ordinary care" employed by a school district and its employees when supervising students must be "extreme care." (Author)