On the eighth anniversary of the Columbine High School massacre and just days after the deadliest shooting rampage in U.S. history at Virginia Tech, Tenafly has canceled all public school classes for Friday.Tenafly High School was evacuated Thursday after a bomb threat was made and students and staff members were sent home early. School officials say the decision to close the schools was influenced by several factors. Among those were Friday being the Columbine anniversary and the possible ripple effect of the Virginia Tech massacre.New Jersey police cautioned that the crime, "creating a false alarm," is a very serious offense. They say it could mean jail time for adults or thousands of dollars in fines for juveniles.