A Centennial Middle School seventh-grader brought a thermometer bulb containing a small amount of mercury to school Tuesday. The bulb broke on his chair during first hour and 19 students in the band class were evacuated. The student said he found the bulb at his apartment complex and brought it to school. After the Phoenix Fire Department and HazMat (hazardous materials unit) evacuated and secured the classroom, library, office area, health office and ISI (in school intervention) rooms, the areas were cleaned and students were checked for mercury on their shoes, clothes and hands. Twelve students were found to have trace amounts of mercury on their shoes, clothing or hands, and although exposure was minimal, families were instructed to consult their family physician for any concerns expressed or additional follow-up needed. A letter was sent home with all Centennial students after school. "The incident was handled efficiently and with great professionalism," Centennial Principal Katherine Miller said. "All 19 parents of the students from the class were positive and supportive of how the situation was handled. The letter to all families was much appreciated by the community."Corinne Frayer can be reached at (480) 898-7917 or firstname.lastname@example.org.