It looked like the driver was trying to make a U-turn and took it too wide.
This is what I thought too - daughter and I saw it around 9:15. She got all upset thinking there were kids on the bus (there weren't - unless they were on and then got picked up). It was a bit of a sight approaching Airport Rd... plus the SHA had a truck parked in back of it with all of the lights flashing, so you couldn't help but look at it.
Hope that whatever happened, there weren't any kids on it when it went in the ditch, and that the driver is ok - it didn't look too serious, just looked like the wheel probably caught in the ditch and they couldn't get it out.