Geologists are warning of the possibility of more rock slides in Utah like one in December that killed a middle-aged couple, flattening their cliff-side home near Zion National Park.

The Utah Geological Society released its report Thursday, saying a massive sandstone slab near the one dislodged by rain and snow in December now threatens to crash and shatter onto the slope below.

Officials say boulders could then crush a string of homes in Rockville, about 250 miles south of Salt Lake City. The report said the force of the rockslide would feel like an explosion.

The report warns residents to pack up and move or understand that they could die if they choose to stay.

The warning comes less than 2 weeks after at least 30 people were killed by a mudslide in Washington state.