A rockslide that killed two residents Thursday afternoon is the first fatal slide in Rockville's recent history, but there have been a handful of near-misses.
In February 2010, a large boulder came tumbling down from the sandstone cliffs overhanging the north and west edges of the small Washington County town, prompting an investigation from the Utah Geological Survey. Their conclusion: Many homes are in danger.
Thursday's slide realized those fears, crushing a home and burying two occupants.
Rockville Mayor Dan McGuire told The Tribune that the residents of the $380,000 house were Maureen Morris, 65, and Jeff Elsey, 58. The bodies had been removed Friday afternoon and were transported to a medical examiner for positive identification.
McGuire said that in addition to grief, "The mood of the town is probably shock and disbelief that it could happen on such a scale. We've had rockslides before, we've had damage before, but we've never had death."
McGuire said a man living in a rental next door left and said he wouldn't return. On the other side of the house lives the mayor-elect, Tracy Dutson, who told McGuire he's staying put.
Tyler Knudsen, UGS project geologist, is in Rockville to assess the cause of the slide and any continuing risk. "There are boulders littering the base of this slope," he said. "What has happened in the past is going to continue to happen in the future."
A 2011 UGS report co-authored by Knudsen came after a large rock that for years had been looming on the hillside finally tumbled downin February 2010. Nobody was harmed, in large part thanks to a previously fallen boulder that it collided with at the base of the cliff. The biggest remaining fragment of the 450-ton rock was just 20 tons, but the pieces were moving fast enough that one rock crashed through one side of a washroom and out the other before damaging two vehicles.
The state report said that a second, 470-ton boulder, 80 feet east from the one that caused the devastation in February 2010, was in a similar position and "continues to threaten the property at 274 W. Main St. and other nearby structures," although Knudsen says Thursday's slide came 500 feet to the west. The report concluded that "rock falls have and may occur without warning anytime and anywhere along the southern slopes of the Rockville Bench."
This is the sixth massive rockfall in the town of 251 since October 2001, when a sleeping resident narrowly escaped injury as a 300-ton boulder annihilated a third of his home. A year later, a car-sized boulder landed on Main Street. In spring 2007, a Main Street motorist collided with a fragment from a rockfall. And in November 2010, hundreds of rocks the largest weighing 78 tons crashed into the cliff base without hitting any property.
Knudsen said Thursday's slide involved a handful of boulders, at least three of which were larger than an SUV.
Springdale Police Chief Kurt Wright told The Tribune on Thursday that Rockville has experienced its coldest weather in 27 years, and the most snow in a century. When temperatures hit 45 on Thursday, he believes the relative heat thawed the rocks and triggered the rockslide.
UGS concluded that rockfalls are most common after rain, freeze-thaw and earthquakes, but they can happen anytime.
Knudsen said there is probably little that homeowners can do to avoid danger. Above highways, pins and meshes are often installed to prevent large rock falls, but the costs are likely prohibitive for a small town and private property owners. "The best way to avoid these problems is to not build in this area," Knudsen said.
McGuire said county ordinances are in place to stop future development, but there are inherent drawbacks to living anywhere in a cliff valley.
"Everybody in Rockville is sort of in a danger zone," he said. "Either from floods or rocks or fire."
McGuire said several hundred citizens showed up within 30 minutes after the rockfall, "Number one, to see what happened, and two, to see what they could do. That's the nature of Rockville."
The Associated Press and Tribune reporters Jim Dalrymple II and Erin Alberty contributed to this story.