Philadelphia music teacher Ed Klein, 55, says the attack that left a Germantown High School math teacher with a broken neck last week was not an isolated incident. Klein would know. He's still recuperating from the broken jaw and concussion he suffered when a student slugged him Nov. 3 inside West Philadelphia High School. The 16-year-old boy punched him after Klein tried to impose discipline in his classes. Klein now wonders if he had given a public account of his attack, the district might have made security improvements that might have prevented last week's assault.