The death toll mounted to 708 people while leaving untold numbers missing and 2 million displaced, wounded or otherwise affected.
According to officials, 5,00,000 houses were destroyed or badly damaged.
Firefighters fired tear gas at looters, who were wheeling off everything from microwave ovens to canned milk at a damaged supermarket across the street.
"We are facing a catastrophe of such unthinkable magnitude that it will require a giant effort to recover," President Michele Bachelet said.
Bachelet also said the country would accept some of the offers of aid that have poured in from around the world.