irefighters worked through the night to finally control a raging fire that tore out a section of the iconic Jersey Shore boardwalk and destroyed dozens of businesses, undoing months of rebuilding from the devastation of Superstorm Sandy.

About 100 firefighters remained on the scene in Seaside Park, N.J., overnight to put out hot spots on the smoldering rubble, but fire officials say the situation was under control as of this morning. At the height of the blaze, more than 400 firefighters, many of them volunteers, were called to the scene as Seaside Park declared a state of emergency.

Only non-serious injuries to firefighters have been reported, according to N.J. Gov. Chris Christie, who was at the scene.

The fire went beyond 10 alarms at one point, according to ABC News station WABC-TV.

"You're seeing little pockets of fire. They're just getting as much water on it as they can to try and get the smoke condition down," Ocean County fire coordinator Brian Gabriel said this morning. "We're going to be putting water on this fire because, understand, some of these buildings have collapsed."

For hours on Thursday, the 20 to 30 mph winds pushed the fire, causing it to burn through a six-block length of boardwalk and cause millions of dollars in damage from Stockton Avenue in Seaside Park to Lincoln Avenue in Seaside Heights.

Late Thursday night, Firefighters dug a trench and tore out a 25-foot swath boardwalk to prevent the furious, wind-whipped blaze from jumping to an area just rebuilt after Superstorm Sandy. Workers piled makeshift sand dunes to hold the fire back.

Firefighters call the maneuver a firebreak. In much the same way as forest fire crews rip out vegetation to deprive an advancing fire of fuel, the boardwalk gambit succeeded in halting the fire's extension any further into Seaside Heights.

N.J. Gov. Chris Christie Calls Seaside Fire An 'Unthinkable Situation'

"The threat of it moving at this point is minimal and emergency workers did an amazing job," said John Camera, borough administrator in the neighboring boardwalk town of Seaside Heights, according to ABC News Radio. "The fire appears to be under control. They'll be people stationed there probably for another day or more and they expect that there may be controlled burning."

Work crews had just completed repairs to the boardwalk destroyed by storm waters just before Memorial Day and in time for a visit from Prince Harry in May. The fire destroyed a length of boardwalk containing perhaps 30 businesses, officials said, near the same stretch of sand where a rollercoaster landed upright in the ocean after Sandy hit the coastline in October 2012.

The fire might have begun Thursday afternoon around 2 p.m. at a Kohr's frozen custard stand on the boardwalk, according to WABC. But officials were hesitant to speculate on a cause for the blaze, or even speak on the record about where it might have started.

Officials told ABC News that the section of boardwalk that burned was the only stretch that was not rebuilt after Sandy. It was part of the old boardwalk that was not destroyed in the storm, they said.

Besides the wild winds, the nature of the construction was seen to be fueling the fire.

"I said to my staff, 'I feel like I want to throw up,'" Gov. Christie told reporters near the fire scene Thursday evening. "And that's me, after all the effort and time and resources that we put in."

Camera thanked Christie for racing to the scene shortly after the fire broke out.

"When I heard him say he felt like throwing up when he first heard it, it was something that all of us could relate to because it just was literally unbelievable," Camera said.

Evacuations were ordered for more than six blocks to the north of the fire, WABC reported.

For many residents, it's yet another setback for the battered Jersey Shore.

"It's devastating. I've been crying all afternoon," Shirley Kreszl, who has rented a summer home in Seaside Park for decades, told The Associated Press. "Haven't we been hit enough? We try to rebuild and just when we think we saved a little bit of our town, this happens. It's just not fair."

ABC News' Josh Margolin and The Associated Press contributed to this report.