Got nothing to do with the cold. Classic tanker F'up, didn't open the cover. It happens fast. When I hauled poop to the treatment plant, one windy night, the cover blew closed. I raced up the ladder, I couldn't open it, so down the ladder and closed the valve. It took a while, but it finally opened with a rush of air. Since then, a tarp strap holding it open fixed that. Then there's the old guy at my ex-BIL's father-in-laws milk business, he got a brand new tank, put his oldest, and therefore, most reliable driver on it, FIRST LOAD, he was at the transfer station talking to an employee about the shiny new tank, forgot the cover and sucked 'er in. That had never happened in all his years.He was so devastated he retired.
That wagon must have been dropped and nobody opened the cover. How would a tractor get away from that?