It was the Presidents Day Holiday, and the Estrada family was barbecuing in the backyard of their Canyon Country home when they noticed cracks in the patio concrete.
That was their first inkling of a slow-moving landslide that in the days since has torn apart two yards, toppled fences, split the trunk of a palm tree in half, and threatened their home, their neighbor's and homes below.
On Friday, building inspectors yellow tagged those four houses, warning the residents there is enough hazard no one should be on the property during the hours of darkness.
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Of added concern to the Estradas is discovering some cracks in drywall and ceilings inside their house.
"Everyone is just trying to figure out what the plan is to get it to slow down or stop," said Stephanie Estrada as she surveyed the damage wrought by the still creeping slide.
She, her husband and three children stayed with friends Thursday night, and now are looking for extended arrangements.
North of the cutline, her yard and that of her neighbors had dropped six to eight feet, and the mass of earth had moved into the back patios of two homes on Trestles Drive, knocking over fences and pushing up the concrete flooring in an area developed in recent years.
Thursday was a sleepless night for the Guillen family, hearing a wall come down behind their home.
"Just kind of heard the crumble, a really loud rumble," said Daphne Guillen. "It was a row of blocks, then another row of blocks, just progressive."
When they came out in the morning they could see the landslide had pushed under the concrete and raised it almost perpendicular to the ground, just feet from their back wall. They began packing to relocate until the threat can be resolved, and did not plan to remain Friday night.
Concerned that further earth movement could break a water main that passes by the slope, authorities throttled down the volume of water passing through the main.
The cause of the slide remains to be determined. There was speculation the wet winter was a factor. Cisco Guillen, Daphne's husband, recalled there had been a smaller slide down the slope after an earlier rain event.
The slope that's failing is on private property, crossing the boundary between two communities, each with their own homeowners' association, and each has hired experts to assess the situation and recommend responses.
Friday, a crew of laborers was placing sandbags in the patios between the slide and the homes on Trestles Drive, to divert any water that may drain down, but not with any expectation of stopping earth movement.