A violent threat made at one Long Island school turned up empty Thursday, but another still looms.

Oceanside High School administrators sent a letter to parents about graffiti written in the girls locker room. The message, "Death to OHS 5-11-07 Die!!," caused the school to increase security Friday. Administrators said closure of the school shouldn't be necessary.

As Oceanside began sweating, things at Sayville High School started to cool off.

"Some kid supposedly wrote in the boys bathroom, 'I will kill on May 10,'" said senior Brittney Pressler.

Sayville district officials said they responded quickly to visibly increase security. There were no attempts to carry out violence.

Still, Suffolk County held a seminar for school administrators and security officials Thursday. The forum is designed to double-check communications plans and tighten the relationship between schools and police.