SEASIDE PARK, N.J. -- Two New Jersey seaside towns, ripped apart last year by a superstorm and newly rebuilt, woke up Friday to the aftermath of a new nightmare -- a raging fire that destroyed it all again.

"I feel like I want to throw up," the state's famously unscripted governor, Chris Christie, said Thursday after racing to the scene.

The Jersey shore is famous for Bruce Springsteen, crowded amusement parks and some of the most praised beaches on the U.S. East Coast. The communities depend on summer tourism.

Superstorm Sandy tore up the coast in late 2012, and the communities raced to prepare for business this summer. Seaside Heights, whose damaged roller coaster became a defining image of the storm, rushed to reconstruct its boardwalk in time for a May visit by Britain's Prince Harry. It finished with only hours to spare.

But on Thursday, the fire that started near an ice cream shop spread to destroy 50 local businesses and caused millions of dollars in damage. It raged for eight hours and destroyed about five blocks of boardwalk.

President Barack Obama praised the first responders who helped fight the fire and pledged support for state and local efforts to rebuild and recover again.

Paul Schneider, who owns three small boardwalk stands, was stunned.

"Everything's gone. I can't believe this is happening again," said Schneider, who had to rip out damaged electrical wiring and replace sodden merchandise after Sandy.

Christie said Friday said the fire was 95 per cent contained, but it could take days to extinguish "hot pockets" at the scene.

The governor said there were only minor injuries, including to three police officers who fell from a moving vehicle.

"I will not permit all the work we've done over the last 10 months to be diminished or destroyed by what happened last night," Christie said.

Seaside Park officials began planning Friday morning to rebuild their part of the boardwalk, at the southern end. Most of the boardwalk shared by the two towns was still intact.

Authorities said there was no immediate indication whether the fire was suspicious or accidental.

Seaside Park borough Councilwoman Nancy Koury said local business owners worked hard to recover from Sandy's devastation, and "now it's all gone."

Firefighters continued to pour water on the hot spots of the smoking ruins Friday.

Authorities began making tentative plans to rebuild the boardwalk.