Stopped semi-truck rear ended by a 4-wheeler, WB I-84 @ MM33 in Idaho

Passed by this one earlier this morning and found this screenshot from a FB video while searching to find info on it. Happened in Nampa, ID on WB I-84

When I passed by earlier before first responders arrived, a semi truck was stopped with triangles out and lights off in one of the center lanes, and was rear ended by an older van. Unsure if the semi truck was stopped for a breakdown or if there was another cause, and unsure if triangles were placed before or after the wreck. A few four wheelers and semi trucks were stopped to offer assistance, but did not look good based on no movement from the van and distraught looks on everyone around.

Hopefully all involved make it out

edit: per info from a few locals on Facebook, semi was stopped with no lights for a bit beforehand and almost caused more accidents beforehand