Just a couple of guesses. It was a medical emergency or the bus driver lost control trying to avoid something in her traffic lane.
Yeah, both drivers* killed, so it might take time to sort this one out.
*Per the report. 2 drivers? A driver and an alternate or monitor?
On Yahoo news it said the bus for some reason swerved to the left side of the road and hit the truck. Then there was a fire.
I can’t imagine losing a child like that.
Distracted by a child maybe? We will likely never know for certain.