Students at Steel Valley Middle School and High School were evacuated twice yesterday because of threatening phone messages after students already had gone out and returned for a routine fire drill.

The evacuations due to the threats occurred from 10:10 to 10:50 a.m. and again from 11:11 a.m. to 12:40 p.m.

In a letter to parents, Superintendent William Kinavey said the district and the Munhall police and fire departments were investigating "with the intent to fully prosecute those responsible."