How do clarks parents die in Smallville?

Clark's biological parents meaning his birth parents - his birth Dad whose name is Jor-El and his birth Mother whose name is Lara, they were murdered by General Zod however his adoptive parents - Martha is still alive however his adoptive Dad Jonathan had a heart attack and that is what in actuality killed him.
Clark's biological parents meaning his birth parents - his birth Dad whose name is Jor-El and his birth Mother whose name is Lara, they were murdered by General Zod however his adoptive parents - Martha is still alive however his adoptive Dad Jonathan had a heart attack and that is what in actuality killed him.