A pack of about 30 wild dogs has invaded an elementary school in Puerto Rico and forced it to shut down. School director Jose Mejias says a pit bull almost attacked a student before employees chased it away and the school was temporarily closed as a safety precaution. Most of the dogs that had entered the school were caught by Wednesday afternoon. About 100 people gathered outside to complain that authorities were too slow to respond to the invasion in the coastal town of Arecibo. Parent William Medina said an estimated 30 dogs were on the loose.