UPDATE: CHP Releases 911 Call Audio from Orland Bus Crash

Click here to listen.

Accident investigators with the CHP are reconstructing how fast a bus carrying high school students was going before its fiery collision with a FedEx truck that left 10 people dead last week.

The exercise is occurring today along a section of I-5 near Orland.

The bus was heading up California's main north-south interstate last week with 44 Southern California students aboard.

Their destination was Humboldt State University.

Five students died, as did three adult chaperones and the drivers of the chartered bus and truck.

PHOTOS: Investigators Reconstruct Orland Crash Scene