Mission Bay High School (MBHS) students returned to class this week following a tense and unusual week-ending day Friday, Oct. 8. That’s when the school was placed on lockdown from approximately 11 a.m. until just before 3:30 p.m. because a male student brought mercury to the campus and contaminated parts of the school. Approximately 1,600 students spent the afternoon locked inside the school, said MBHS principal Fred Hilgers. Mercury is a silver metal in the form of liquid at normal temperatures, and is known to be highly-poisonous. Seven students and one teacher were exposed, said San Diego Fire Rescue Department spokesman Maurice Luque. Two of the students tested had unsafe readings and both were given showers and fresh clothes to ward off the contamination. The fire department was on scene for the duration of the afternoon and a hazmat crew checked 11 rooms for contamination. Two of those rooms — a computer room and a science room — had high readings. Carpets in one of the contaminated rooms were removed. Officials checked an additional 140 students for contamination. Each of those students had entered the contaminated rooms at some point in the morning. Two other schools in the San Diego Unified School District, Toler Elementary School and Bay Park Elementary School, were also placed on lockdown and hazmat teams were looking into contamination at those locations because the bus carrying the student who brought the mercury also transported students to those schools. Hazmat officials determined that the bus driver, who is from southeast San Diego, was also contaminated and his house was checked for contamination Friday. The mercury was reported to school officials just before 11 a.m. when the student reportedly showed an ROTC instructor the open mercury on a sheet of paper. “It was a great pick-up by the teacher,” Hilgers said. He added that the school had coincidentally completed safety training on Oct. 4. Hilgers also had to be tested for contamination because he had entered one of the contaminated rooms. He said he was fine and showed no contamination. Hilgers remained in direct contact with city officials throughout the emergency. The students were not permitted to have any food during the chemical contamination investigation. The school was placed on lockdown prior to lunchtime. However, Hilgers said, the cafeteria staff was ready to feed the students as soon as they could. He said that his students would not go home hungry. “We are taking small groups of kids to the bathroom,” Hilgers said Friday. The students were at first not allowed to use restrooms, as it is protocol for lockdown. Officials do not believe that the mercury was brought to the school with malicious intent, but rather as something of a curiosity to show to others. The student’s name has not been released. “He’s very upset about the distress he’s put all of his friends and his school through,” Hilgers said.