Two Florida middle schoolers with an apparent interest in the Columbine High School massacre were allegedly plotting to carry out a school shooting of their own until a teacher was tipped off about a possible concealed weapon, authorities said. The teacher at Harns Marsh Middle School in Lehigh Acres, near Fort Myers, alerted school administrators and a school resource officer about the tip from students Wednesday, authorities said. ... ....The two students, who were both known to authorities as deputies had visited their homes nearly 80 times combined, will be charged with conspiracy to commit a mass shooting, according to...