From looking at all the pictures and video in the aftermath of the accident, I notice that the shelter is just beyond a bridge that Buses must travel under, and there appears to be a lot of ice, just past the bridge, that may have been formed from water flowing off the bridge, and onto the transitway between the underpass and the shelter, and right by the curb, that the Bus jumped.
Now, I don't ride public transit that much, but from experience and feedback from those who do, drivers tend to exceed the speed limit, on a regular bassis, while on the Transitway.
Yesterday, with all the ice built up along the part of the transit-way, and the black ice that forms when buses continuously passes over the same spot(s) while either braking or accelerating, with the low temperatures, was NOT a good day to exceed the speed limit.
I'm not suggesting this is the cause, but one of the factors that appears to have been involved from what I saw. I would not rule out distracted driving, but can in no way think that it would be terrorism as suggested.
