(Peterborough, N.H.)  A major explosion at the New Hampshire Ball Bearing Co. In Peterborough this afternoon has injured at least 15 people. Peterborough police say that two people were seriously injured and  taken to the hospital with what were described as non-life threatening injures. Emergency crews from  multiple communities responded to the plant. Local hospitals have been asked to prepare for patients who may have been exposed to hazardous materials. The company manufactures high tech parts for the aerospace industry.