A Santa Cruz pre-school was placed on lockdown as a precaution yesterday morning after someone reported seeing a man with a gun on school grounds. Students at the school on the 800-block of Branciforte Avenue were told to shelter in place at about 9 a.m. while police investigated the area. According to emergency dispatchers, no one was found and the area was deemed safe shortly afterwards. No one was harmed or injured during the lockdown.