This article has been updated with information about water issues firefighters encountered.

A 6-alarm fire that erupted Thursday on a newly rebuilt boardwalk on the Jersey shore is mostly contained, with officials now beginning to investigate the cause. The fire started in Seaside Park and spread to parts of Seaside Heights.  The fire leveled more than 50 local businesses in Seaside Park, causing millions of dollars in damage.

The fire raged for about eight hours. A fierce wind spread the flames quickly. In addition, a Seaside Park official said the location of the fire, on the boardwalk,  made it hard to access the blaze:  fire trucks would have sunk into the sand if they were place there. And there was not enough space on the street-side of the boardwalk for all of the trucks to connect to fire hydrants there.

Pumps had to be brought in from as far away as Elizabeth, about 45 miles to the north, the official told WNYC’s Janet Babin. The pumps conveyed water through fire hoses from a nearby bay and swimming pools to the scene of the fire. The official did not want his name used because he was not authorized to speak to the media. He added that it is likely that both towns will want to complete a full hydraulic analysis to determine whether alternatives should be in place to fight fires that erupt on the boardwalk.

New Jersey Governor Chris Christie visited the site on Thursday evening and Friday morning and said the infrastructure of the towns was still not fully repaired from Sandy more than 10 months ago.

 “All these infrastructure systems are going to take time to rebuild to 100 percent capacity,” Christie said. “We had significant capacity last night through the water system. But we also had a fire that was being fed from 30 mile-an-hour winds out of the south.”

 But the Seaside Park official challenged the notion there were any infrastructure problems. He said generators for the town’s water system had to be replaced, but that the work was completed months ago.

Officials say more than 400 firefighters were dispatched to fight the fire. The blaze destroyed the Seaside Park section of the boardwalk, but makeshift sand dunes saved the northern portion in neighboring Seaside Heights. The damage was contained to commercial property, with the exception of a small fire on the roof of a condo complex that was put out. 

Ocean County Fire Coordinator Brian Gabriel described what the scene was like at a press briefing Friday morning.

"Just picture a 50 foot wall of fire, about a hundred feet high, just coming at you." he said.

Justin Auciello of Jersey Shore Hurricane News, a lifelong resident of the area, said the fire was painful to watch.

"You know, I'm watching my childhood go up in flames right now, literally. I mean, I grew up two miles down the road." he said. "It was always can we please go to the boardwalk? Can we please get ice cream? And I'm watching it right in front of my...right here. Just go up. It's been very very tough for me."

The massive blaze burned four blocks of boardwalk in each of the neighboring communities. Seaside Heights public works crews ripped out 25 feet of the newly-rebuilt boardwalk and filled the hole with sand piles to block the flames from spreading further.

New Jersey Public Radio's Terri Langford attended a briefing in Seaside Park Friday morning. She said that investigators, including ones from the Ocean County prosecutor's office and the Ocean County Fire Department, begin the task of trying to determine what sparked the blaze.  "The fire department won't comment one way or the other until the investigation is complete," she said. The Bureau of Alcohol, Tobacco, Firearms and Explosives is also joining the investigation.

Authorities say there is no immediate indication whether the fire was suspicious or accidental. No serious injuries were reported. 

Thursday, September 12th --

Gov. Chris Christie spoke to the media Thursday evening about the raging fire enveloping approximately six blocks of Seaside boardwalk businesses.

Christie said when he heard about the fire, "I said to my staff, I feel like I want to throw up. And that's me. After all the effort and time and resources that we've put in to help the folks of Seaside Heights and Seaside Park rebuild...to see this going on it's just unthinkable.

The boardwalk had been rebuilt this past summer with new, treated pine after the storm.

Christie also warned residents not to come to the boardwalk to check on summer homes or any other reason. More spectators would likely get in the way of first responders, he said.

"My advice to you, in fact my admonition to you, is — do not come here . . . . Do not travel. Stay away," he said.

Kristi Funderburk of the Asbury Park Press had earlier told WNYC that the firefighters "ripped up the boardwalk in Seaside Heights," in order to make a first firebreak, but "the fire was able to jump that fireline and continued north." 

Television footage showed flames and thick black smoke billowing from a long stretch of the boardwalk in Seaside Park, spreading into nearby Seaside Heights. Christie said that the fire seemed to be halted at the second firebreak.

Seaside Heights Police Chief Thomas Boyd said tar roofs and stiff winds were fanning the flames. He said a section of boardwalk was being removed to create a fire line to keep the blaze from spreading. He said the fire created embers the size of a fist.

The fire is believed to have started in a Kohr's custard shop Thursday afternoon. Firefighters from as far south as Cape May are aiding in the effort to contain the six alarm blaze.

Authorities say several firefighters and residents were being treated for smoke inhalation. No other injuries were reported.

With reports from the Associated Press.