Thousands of evacuated residents waited to return home Wednesday while many others faced commuting headaches as propane from an overturned tank truck burned for a second day.

The fire was so intense, and potentially explosive, that firefighters were prevented from approaching the burning truck loaded with about 2,500 gallons of propane. Instead, unmanned pumpers threw water on the blaze.

Officials estimated that the fire could burn for as long as 30 hours, or until about 3:30 p.m. Wednesday, if no explosion occurred.

About 2,000 families were evacuated from within half a mile of the accident and taken to a nearby church, said Hank McCann, a Nassau County police spokesman.

County police Lt. Willard Krausch said the truck overturned Tuesday morning on the Seaford-Oyster Bay Expressway after the driver experienced a problem with the truck's rear wheels.

A section of the highway and of another nearby road were closed, and the Long Island Rail Road was forced to suspend all commuter rail service on a nearby line.