The family of three schoolgirls involved in a fatal school bus crash in southern New Jersey last week is offering thanks to all those who have supported them.

Triplet Isabelle Tezsla was killed and sisters Natalie and Sophie were severely injured. Their father is New Jersey State Trooper, Sgt. Anthony Tezsla.

Natalie was upgraded from critical to stable condition last Friday. Sophie remains in critical condition, along with classmate Jonathan Zdybel.

The Tezsla family said in a statement Tuesday that the outpouring of love and support has touched them profoundly. They also thanked rescue workers, doctors and nurses for their efforts.

The National Transportation Safety Board is investigating Thursday's crash between the bus and a dump truck in Chesterfield. No charges have been filed against either driver.

(Copyright 2012 by The Associated Press. All Rights Reserved.)