Philadelphia October 18, 2017 11:12 am Philadelphia School Lockdown Lifted NBC10 was live on the scene when the lockdown was lifted on Overbrook High School after a teacher thought she heard a gunshot. No evidence of a shooting was found, police said. US & World Videos 0:19 Body of missing kayaker found in the Schuylkill River 2:00 Police officer placed on administrative duty after killing dog that attacked a man 0:51 Police officer shot and killed 1 of 4 dogs that attacked a 53-year-old man 1:49 ‘We have to do better': Philly teen dedicates her Instagram to humanizing victims of gun violence 1:22 Video shows man walk up to ring doorbell with an apparent gun, police say