Locals call the mix of heavy snow plus rain, "Sierra concrete". Firefighters are blaming the Saturday night collapse of two roofs in Pollock Pines on it.
"I think this is a pretty unusual winter and now spring and we've gotten 3 feet of snow in the last 72 hours and then it rained," said Michael Hardy of the El Dorado County Fire Department.
The collapses happened at a True Value Hardware store and Knotty Pine Lanes, a bowling alley, in the small El Dorado County community. The physics of the collapses are pretty simple. A gallon of water weighs 8.3 pounds and the section of roof that collapsed at Knotty Pines was 40 feet by 40 feet. "You have several tons of additional weight on this roof," said Hardy.
The bowling alley has been red-tagged, deemed unsafe for people to be inside, but the destruction could have been much worse than structural failure. Sherrie Schier and 30 of her dance students were having a sleepover inside their studio, which shares space with Knotty Pines, when the roof collapsed. They heard the rafters buckle, "The firemen met us at the door, came in and told us to evacuate," said Schier.
All over Pollock Pines Sunday afternoon, people were on their rooftops with shovels and rakes trying to get the heavy snow off -- and hopefully prevent a collapse of their own.