A group of on-duty Sanitation supervisors is under investigation for allegedly buying booze and chilling in their cozy department car for hours Monday night after the blizzard stranded a bus and three snowplows blocks away…

The four remained in the idling sedan until morning — then told their bosses they could do nothing about the blizzard because they had run out of gas, one witness said.

“They just sat in their car all night with the heat running,” the witness said…

Customers who saw the group buying beer at the Ocean Mini Mart at 3917 18th Ave. in Kensington shouted at the workers.