It may be possible to find out how fast the truck was going, as GM vehicles have, for some years, had a "black box" similar to a flight data recorder, that keeps track of that, and several other things as well. However, exactly who has the right to access that data is a sticky legal issue, with quite a bit of variation from state to state.

Any word on whether alcohol was involved?

An ill-handling vehicle and excessive speed is often a deadly combination, adding intoxication to the equation multiplies the danger severalfold.

Then there are the factors that are harder to determine---was the driver local (and presumably familiar with the road) or was he seeing a tricky curve for the first time? Did the right front tire perhaps have a slow leak, and was down to something like 18 psi, causing it to tuck under instead of providing cornering grip?