Eight-hundred tons of rock plunged to the ground behind the Ahwahnee Hotel at Yosemite National Park the other day, injuring no one but damaging a windshield in a parked car.

The rockfall last Thursday was attributed by park geologists to the usual freeze-thaw cycles that are common in the park during the winter months.

The rockfall occurred shortly after 5 p.m. January 29 from high on the cliff-face west of Royal Arches and east of the "Rhombus Wall." The rock struck bedrock ledges and finally landed on the large talus slope behind the Ahwahnee Hotel, according to park officials.

"These impacts produced a large dust cloud and many small 'flyrock' fragments. All of the large rock debris stayed on the talus slope, but some 'flyrock' fragments extended beyond the edge of the talus slope, entering the north side of the Ahwahnee parking lot," they added. "One vehicle sustained windshield damage, but there was no other damage reported, and no injuries.

The Yosemite Valley is no stranger to rockfalls. Last October a substantial rockfall from the cliffside below Glacier Point led to a decision to permanently close roughly one-third of Camp Curry's tent village out of safety concerns.