BODEGA BAY -- A 10-year-old boy from Arizona, visiting the Bay Area with his family, has been killed when a cave he and his brother were digging at a beach near Bodega Bay collapsed and buried him six feet deep in sand.

The unnamed boy and his brother were apparently tunneling into the side of a sand dune situated under a 40-foot tree at Salmon Creek Beach, according to Bodega Bay Battalion Chief Mike Elson.

While they were digging, the large tree fell over, causing the tunnel to collapse, Elson said.

Emergency crews learned of the incident at around 3:40 p.m. Saturday. It took almost an hour for rescuers to dig the boy out from under the sand, Elson said.

Subsequent resuscitation efforts failed and he was pronounced dead at the scene.

The boy's brother was only partially buried and was able to dig himself out and run for help. He was uninjured, Elson said.

Fire officials could not provide any further information on the accident.