SAN DIEGO — The main entrance to North Island Naval Air Station on Coronado shut down for several hours Tuesday after a driver was found with possible bomb-making materials, a base spokesperson said. The incident started about 9 a.m. when a driver approached the gate and was stopped at the request of Naval Criminal Investigative Service officials, Naval Base Coronado spokesman Kevin Dixon said. Security officers noticed possible bomb-making materials in the vehicle, but the materials were not assembled into any kind of device, Dixon said. NCIS took the sailor driving the vehicle in for questio…