(CNN) — Superstorm Sandy left Seaside Park's boardwalk damaged yet reparable a year ago, but the flames that raged for nine hours Thursday consumed four blocks of it.
The fire was under control by evening, but only after a 20- to 25-mph wind fueled the fire, which began at an ice cream shop, carrying embers to a nearby condominium complex, pier and an arcade, city and county officials said. Those later blazes were contained.
By the time firefighters had everything under control, the fire had destroyed or damaged 50 businesses, CNN affiliate WCBS reported.
There was a firefighter convention in Wildwood, 90 miles south, at the time, so roughly 400 firefighters from 30 towns -- many of them volunteer units -- were able to respond, said Mayor Bill Akers.
"We're just so grateful for what these gentlemen do every single day, putting their lives on the line to save life and property, in other communities, not just their own," he said.
About 100 firefighters were still on the scene early Friday, said Ocean County Fire Administrator Brian Gabriel. There were no civilian injuries and "one, maybe two very, very minor firefighter injuries," he said.
"I feel like I want to throw up," said Gov. Chris Christie after witnessing the fire Thursday. "After all the effort and time and resources that we've put in to help the folks in Seaside Park and Seaside Heights rebuild. To see this going on ... is just unthinkable."
The Seaside Heights boardwalk was in the public eye shortly after Superstorm Sandy blew its famous Jet Star roller coaster into the water. The coaster was removed from the ocean in May, shortly before the boardwalk reopened for business.
Firefighters ripped out the boardwalk at Lincoln Avenue in time to create a fire line that saved much of Seaside Heights from the fate that imperiled neighboring Seaside Park.
They dug a 20-foot trench where the street met the boardwalk to keep the brisk winds from further spreading the flames, Christie said Thursday.
"The destruction south of Lincoln Avenue, it's complete," he said.
Town officials plan to meet with business owners and help them rebuild, said Town Administrator Robert Martucci. Akers added that the town will also assess the damage.
"If there's a silver lining, we just built it. We have the specs. We know what we're doing," the mayor said. "We'll get it back up."
Authorities are not yet sure what caused the fire, but Martucci said it started at Kohr Brothers Frozen Custard shop on the FunTown Amusement Pier around 2:15 p.m. Martucci was at a meeting at town offices across the street when it began.
The fire escalated to six alarms shortly before 4 p.m. ET.
Sandy destroyed the FunTown Pier. It was partially reopened this summer. The storm also damaged local water systems, and firefighters struggled with the supply Thursday, Christie said.
They had to tap into Barnegat Bay seawater to extinguish the flames.