The more than 400 students are attending classes Thursday at a refurbished school in a neighboring town that has been given the same name as their old school.
The school district says parents who want to be close to their children are welcome to visit and stay in classrooms or an auditorium throughout the day. Parents were encouraged to have their children take the bus to help them return to familiar routines.
The gunman, Adam Lanza, killed his mother before going on the rampage at the school on Dec. 14 and then committing suicide. Police have not offered a possible motive.