GRANITEVILLE--Gov. Mark Sanford on Wednesday asked for federal disaster assistance for Aiken County in connection with the damage from a train crash and resulting chemical spill that killed nine, injured 250 and forced thousands of residents from their homes for a week.

Sanford asked President Bush and the U.S. Small Business Administration that the county be made eligible for federal financial assistance and low-interest rate loans.

State and local officials said work had begun emptying the third tanker that was carrying chlorine.

Work began just after midnight to empty the car, which could take as long as 24 hours.

Chlorine gas leaking from a damaged tanker car has been blamed for the nine deaths in this small textile town near the Georgia state line. The car was damaged when an oncoming Norfolk Southern train crashed into cars parked on a side track.

Many of the residents evacuated from a 1-mile area around the crash site awaited word Wednesday on when they would be able to return to their homes.

Norfolk Southern was continuing to operate its assistance center in Aiken to help residents who were displaced.

The company said Wednesday that more than 2,500 people had received payments.

A group of Charleston law enforcement officers is preparing to travel to Graniteville to provide security during the extensive cleanup.

The Charleston County Sheriff's Office is sending a dozen deputies, Capt. Dana Valentine said. Some deputies will go to Graniteville today and some will report Friday.

Another group of local law enforcement officers is expected to return home Friday. Sixteen Charleston Police Department officers and the Mobile Cook Wagon have been in Aiken County since last week. Their primary duty is to feed emergency workers. Department spokesman Charles Francis said those officers will return Friday, unless asked to stay longer.

Charleston County deputies will provide perimeter security at the spill site and help in securing the containment area, Valentine said.

They will be equipped with protective gear the sheriff's office recently bought with Homeland Security money. The gear includes chemical detectors and an escape pack containing an oxygen tank and hood.

The deputies probably will remain in Aiken County until next week, Valentine said. Deputies volunteered for the duty.

"There's actually been a lot of people who asked if they could go," she said.