I'd say late 80's/early 90's GM pickup in carpool lane to the left. If you watch close enough you can see it drop as it loses it's tire. I should have fallen further back... once I saw sparks I immediately turned on hazards and fortunately had a good 1/8 mile of clear behind me.
Video:
https://goo.gl/photos/DT4FFwpL5g3iRGTg7
Video:
https://goo.gl/photos/DT4FFwpL5g3iRGTg7