"Did the article say the BMW was stolen?"
No word on that in any of the follow on articles, so I'm assuming no.
"It mentioned the BMW collided with a Toyota turning left which would happen if they were going too fast and not paying attention."
The intersection where this happened is less than a half mile from my house, the road on which it happened is the one I take to work every day. That road is signed at 35 MPH. At the best of times speeds often 5 to 10 higher than that for the slower cars. A lot of cars treat it as a drag strip.
The sight lines, though, especially in the direction the Toyota was pointing, are pretty good, so my guess is that the Toyota either misjudged how fast the BMW was moving or simply didn't see him because he/she was more focused on making sure the three girls who were hit were clear of the intersection.
I've seen multiple news reports saying that the BMW was traveling at a "high rate of speed."
My guess, based on the damage to both vehicles as well has how far the BMW traveled, is that it was going at least 55 mph, and probably over that.