U.S. Coast Guard visits grounded Shell rig

Chinook helicopters send water spraying into the air as they land on Kodiak Island, off the coast of Alaska.

On Saturday, a U.S. Coast Guard team began investigating how a Royal Dutch Shell drillship ran aground in shallow waters nearby.

The Kulluk oil rig has been stuck here since being engulfed in a New Year's Eve storm.

Salvage experts visited Wednesday and Thursday to assess the rig.

Although some of the drillship's equipment has been damaged by waves and flooding, it has not spilled its 155,000 gallons of fuel and other petroleum products into the ocean as yet.

Members of the U.S. Congress have also called for an investigation into Shell's arctic offshore drilling operations.