Mega-storm Sandy caused "unthinkable" damage to the Jersey Shore, the barrier islands and beach towns that run the length of New Jersey's Atlantic coast, Governor Chris Christie said Tuesday.

Christie's state was on the path of the hurricane when it slammed ashore Monday night, unleashing coastal flooding and killing at least three people in the state, officials say.

Hundreds of people had been rescued by Tuesday morning, Christie said at a press conference after surveying damage left by Sandy. "We'll have to rescue hundreds more," he added.

"The level of devastation at the Jersey Shore is unthinkable," Christie said.

Currently state officials are focused on "search and rescue and restoration of power" in the hardest-hit areas.

"State police and national guard helicopters are in the air as we speak engaging in coastline rescue efforts," said Christie. "Our swift water team is positioned in Atlantic City and has begun rescue and recovery for those who remained."

There are more than 5,500 residents in state and local shelters, Christie said, and state officials were working with humanitarian relief groups, including the Red Cross, to provide meals.

Christie also said 2.4 million New Jersey households were without power.

"This is twice the number of impacted households as Hurricane Irene," he said, referring to the powerful storm that struck the region in August 2011.

To restore power quickly, New Jersey power companies are getting help from utility workers "from states as far away from Texas and Indiana and even folks coming in to us from Canada," he said.

The storm also caused "major damage on each and every one of New Jersey's rail lines.

"Large sections of track were washed out on the New Jersey coastline. Numerous power lines and trees have fallen" along tracks, and "several rail bridges were damaged by storm surge including boats and other debris lodged on the railroad tracks," Christie added.