Two men were being questioned by police today after a landmark Victorian pier was destroyed by fire.
Up to 95% of Hastings pier was ruined as emergency services struggled to get the blaze under control in the early hours.
Sussex Police said two males were arrested and were being quizzed about the cause of the fire. The pier has been closed since 2006.
More than 60 firefighters with eight engines were trying to extinguish the blaze, East Sussex Fire and Rescue Service said.
Emergency services were alerted to the fire by a member of the public at 1am.
Simon Rose, spokesman for East Sussex Fire and Rescue Service, said: "It's still a major blaze. There's about 60 firefighters dealing with the blaze.
"At the moment about 95% of the structure has been destroyed. It's quite significant."
There were no reports of any injuries.
Campaigners in Hastings were trying to raise money to see the pier refurbished with modern attractions.
The council said it was prepared to buy it by compulsory purchase after a study this summer showed it could be made safe for £3 million.
But Dale Turner, who runs the Seaspray bed and breakfast opposite the pier, attacked authorities for failing to secure its safety in time.
"This is the sort of thing people were worried about," the 55-year-old said.
"The pier had been allowed to fall into ruin and now we may never get it back."
He said a series of blasts were heard as the pier caught fire after 1am. It was still smouldering this morning, he added.
Mr Turner, who has run the guesthouse with his wife Jo for 11 years, said: "I did not see anything in the night as we hear a lot of noises - my wife just assumed the explosions were the lifeboats going out to sea.
"There were at least four loud bangs after 1.15am. The firefighters have been spraying the pier all morning but I don't think they are actually on the pier.
"The worry for everyone now is exactly how much damage was done. The whole thing was in line for a facelift but, if the structure was hit, it could be very expensive indeed.
"I don't know whether it was insured or not."
The pier was owned by Panamanian-registered company Ravenclaw.
On a "Save Hastings Pier!" Facebook page, members reacted with shock to the blaze.
Robbie Clark wrote "it's so wrong!', while Martyn Reed, from Hastings, added "can't believe the pier's been burnt down!!!!"
Designed by Eugenius Birch, Hastings pier opened in 1872 and was originally 910ft long.
Firefighters were transported to the blaze by local RNLI lifeboats.
Fire service spokesman Mr Rose added: "It's a very historic building and landmark for Hastings. The priority for the firefighters is to preserve as much of the structure as they can to see if something can be done with it in the future."
A spokesman for Sussex Police said: "The origins of the fire are still being investigated and at this time two males have been detained for questioning.
"Sussex Police and Sussex Fire and Rescue are still dealing with the fire and advise anyone driving in the area of the A259 in Hastings to take alternative routes."
It is the latest of a string of historic piers to be hit by fire.
In July 2008, Weston-super-Mare pier was destroyed, while Brighton, on the East Sussex coast, experienced a devastating year in 2003.
The ill-fated West Pier suffered two major blazes within two months after parts of it had already crumbled into the sea.
Problems have beset the pier at Southend-on-Sea in Essex during its long history.
In October 2005, a blaze caused major damage to the pier, leading to the closure of part of it for 10 months.
Thick plumes of smoke billowed high into the air above Hastings, making it difficult to see the remains of the pier.
Part of the A259 along the seafront was closed, causing congestion in the morning rush-hour as motorists were diverted through the town.
A small crowd gathered at the police cordon opposite the pier.
Local man Tim Hall, 45, said he was "gutted" by the sight of the burning structure.
He said: "It was the heart of the town, I'm totally gutted.
"I've lived here all my life and used to go on the penny slot machines on there when I was a kid.
"I was really looking forward to it reopening."