Yes, That's My Kid in the Upside-Down Bike Trailer in the Middle of the Street
I don't know what happened. I was crossing the two eastbound lanes of Mass Ave when I felt my bike pulling me sideways. I managed to unclip and look back. Max was kind of screaming. I was staring at the bottom--not the side, but the bottom--of the trailer.
And I was off my bike and flipping the trailer upright, and some stranger was helping me pick up all the spilled groceries*, and I got us over to the sidewalk and crouched down and stared at Max.
He seemed fine for a child who'd just been upside-down in the middle of the road in a bike trailer.
I tightened his waist strap though it was tight enough, put his chest strap on (no, he wasn't wearing it when the trailer flipped), and we had a very uneventful ride home.