ATLANTIC CITY, New Jersey (AP) — Superstorm Sandy slammed into the New Jersey coastline and hurled a record-breaking 13-foot (43-feet) surge of seawater at New York City last night, roaring ashore after washing away part of the Atlantic City boardwalk and putting the presidential campaign on hold.

Just before its centre reached land, the storm was stripped of hurricane status, but the distinction was purely technical, based on its shape and internal temperature. It still packed hurricane-force wind, and forecasters were careful to say it remained every bit as dangerous to the 50-million people in its path.

The National Hurricane Centre announced at 8:00 pm that Sandy had come ashore near Atlantic City. The sea surged a record of nearly 13 feet (four metres) at the foot of Manhattan.

In an attempt to lessen damage from the storm, New York City's main utility cut power to about 6,500 customers in lower Manhattan. Authorities worried that seawater would seep into the New York subway and cripple it, along with the electrical and communications systems that are vital to the nation's financial centre.

As it closed in, Sandy knocked out electricity to more than 1.5 million people and figured to upend life for tens of millions more. It smacked the boarded-up big cities of the north-east corridor, from Washington and Baltimore to Philadelphia, New York and Boston, with stinging rain and gusts of more than 85 mph (135 kph).

As it made its way toward land, it converged with a cold-weather system that turned into a fearsome superstorm, a monstrous hybrid consisting not only of rain and high wind but of snow. Forecasters warned of 20-foot (66-feet) waves bashing into the Chicago lakefront and up to three feet of snow in West Virginia.