Alrazi Academy - erratic school bus driver behavior

This morning on my commute to work I noticed a school bus tailgating a semi truck/trailer on University Ave and it caught my eye, because usually bus drivers of all kinds are extremely careful and defensive drivers.

I was headed the same way and with the natural flow of traffic I found myself in the lane next to it and about 4 car lengths back.

This section of University has a 45 mph speed limit that goes down to 40, with lots of dump trucks, semis, heavy industrial traffic. It's also rather narrow.

Completely out of the blue, the bus switches on its red lights, swings out its stop sign, and comes to a halt on University. Tires on other vehicles squealed. The Ankeny Sanitation truck behind the bus struggled to avoid rear-ending it.

I managed to stop, but a loaded dump truck unfortunately was not able to, and limped past. I couldn't actually see if any children got on the bus, its right side was hidden from view.

No yellow lights, no slowing to a stop, the whole thing was extremely bizarre and I was immediately curious and concerned for the occupants.

I don't know anything about Alrazi Academy, I'm just posting for community awareness as I wouldn't want my children on that bus.