* At least 93 dead, cost estimated at up to $50 billion
* Rescuers search house-to-house in coastal towns
* Gasoline shortages add to anxiety in face of long recovery
NEW YORK/SEASIDE HEIGHTS, N.J., Nov 1 (Reuters) - Rescuers searched flooded homes for survivors, drivers lined up for hours to get scarce gasoline and millions remained without power on Thursday as New York City and nearby towns struggled to recover from one of the biggest storms ever to hit the United States.
New York City subway trains crawled back to limited service after being shut down since Sunday but the lower half of Manhattan still lacked power and surrounding areas such as Staten Island, the New Jersey shore and the city of Hoboken remained crippled from a record storm surge and flooding.
At least 93 people died in the ``superstorm'' that ravaged the northeastern United States on Monday. Officials said the number could climb as rescuers searched house-by-house through coastal towns.
``I worked all my life, and everything I had is right there,'' said Bob Stewart, 59, standing on the Jersey Shore beach in the town of Seaside Heights and looking at the pile of debris that was once his home. ``I put my life right there.''
The financial cost of the storm promised to be staggering. Disaster modeling company Eqecat estimated Sandy caused up to $20 billion in insured losses and $50 billion in economic losses, double its previous forecast.
At the high end of the range, Sandy would rank as the fourth-costliest U.S. catastrophe ever, according to the Insurance Information Institute, behind Hurricane Katrina in 2005, the Sept. 11, 2001, attacks and Hurricane Andrew in 1992.
The devastation threatened to disrupt Election Day next Tuesday, though President Barack Obama, in a tight race with Republican challenger Mitt Romney, appeared to gain politically from his disaster relief performance.
New Jersey Governor Chris Christie, a vocal Romney supporter, praised Obama, and New York City Mayor Michael Bloomberg, a political independent, endorsed Obama on Thursday.
Meanwhile, the hunt for gasoline added to a climate of uncertainty as Sandy's death toll and price tag rose.
``I'm so stressed out,'' said Jessica Bajno, 29, a school teacher from Elmont, Long Island, who was waiting in line for gas. ``I've been driving around to nearby towns all morning, and being careful about not running out of gas in the process. Everything is closed. I'm feeling anxious.''
Some residents may lack electricity for weeks. New York utility Consolidated Edison restored power to 250,000 customers, leaving another 650,000 in the dark.
The vast majority will be restored by the weekend of Nov. 10-11 but ``the remaining customer restorations could take an additional week or more,'' the company said.
About 4.6 million homes and businesses in 15 U.S. states were without power on Thursday, down from a record high of nearly 8.5 million.
More deaths were recorded overnight in the New York City borough of Staten Island, where authorities recovered 17 bodies after the storm lifted whole houses off their foundations. Among the dead were two boys, aged 4 and 2, who were swept from their mother's arms by the floodwaters, police said.
In all, 38 people died in New York City, officials said.
``It was like living through Titanic but on ground,'' said Krystina Berrios, 25, of Staten Island, looking at her bedroom caked in mud, furniture upended. ``You would never think in a million years having to live through something like this.''
Sandy started as a late-season hurricane in the Caribbean, where it killed 69 people, before smashing ashore in the United States with 80 mph (130 kph) winds. It stretched from the Carolinas to Connecticut and was the largest storm by area to hit the United States in decades.
JERSEY SHORE FLOORED
In hard-hit New Jersey, where entire neighborhoods in oceanside towns were swallowed by seawater and the Atlantic City boardwalk was destroyed, the death toll doubled to 12.
Floodwaters finally receded from the streets of Hoboken, across the Hudson River from Manhattan, leaving behind a stinky mess of submerged basements and cars littering the sidewalks.
``The water was rushing in. It was like a river coming,'' said Benedicte Lenoble, a photo researcher from Hoboken. ``Now it's a mess everywhere. There's no power. The stores aren't open. Recovery? I don't know.''
New Jersey favorite sons Bruce Springsteen and Jon Bon Jovi, along with Christina Aguilera, Billy Joel and other stars, will headline a benefit concert for storm victims Friday on NBC television, the network announced.
The Federal Emergency Management Agency agreed to cover 100 percent of emergency power and public transportation costs through Nov. 9 for affected areas of New York and New Jersey, up from the traditional share of 75 percent.
More than 36,000 disaster survivors from New York, New Jersey and Connecticut have applied for federal disaster assistance and more than $3.4 million in direct assistance has already been approved, White House spokesman Jay Carney said.
The Pentagon was airlifting power restoration experts and trucks from California to New York to assist millions of people still living in darkness.
Fuel supplies into New York and New Jersey suffered from idle refineries, a closed New York Harbor, damages to import terminals, and a closed oil pipeline.
The scarcity of fuel, electricity and supplies made cleanup more daunting for barrier towns.
Seaside Heights residents who obeyed the mandatory evacuation order were cut off from their homes. The entire community was submerged by the storm surge, which washed over the island and into the bay that separates it from the mainland.
Chris Delman, 30, saw a photograph of his house in a local newspaper on Wednesday. It was still standing.
``We ain't living in Seaside no more, that's obvious,'' Delman said. ``I just want to know what I have left.''