PASADENA, Calif. (KABC) -- Crews are digging a 15-foot-trench to determine if shallow earthquake faults beneath San Rafael Elementary School in Pasadena pose a danger to students.The soil at the bottom of the trench will help a team of geologists determine if the four fault lines below the school are active.If the fault lines are found to be active, the 100-year-old school will be forced to close down and the 400 students will be transferred to the old Allendale Elementary School campus in 2017."I attended this school as a child a while ago and it's become a very central part of this neighborhood," parent Emily Mencken said.The test results are due back in a couple of months. If they show that the fault lines are not active, the Pasadena Unified School District will move forward with plans to renovate the school.