So I talked to my friend Angela a couple days later and she saw the event on the news, she was able to clear up a few things.
What happened was as the bus was driving towards the bridge its engine caught on fire. Somehow this fire also disabled the bus’s brakes so it was driving out of control. (Think the movie speed)
The nearest police officer to the bus heard about this and then about halfway up the bridge he rammed himself into the from of the bus to stop its motion. Ramming the bus here must have created the fire on the bridge.
The police officer was then sent backwards on the bridge away from the fire and the bus after loosing most of its momentum must have slowly coasted down the small incline to get to the bottom of the bridge.
When this happened the passengers managed to get off the bus safetly before it really went up in flames. No one was killed!
Quite a crazy chain of events!