Two major aftershocks hit central and northern Taiwan today as the death toll from Tuesday's powerful earthquake rose to more than 2,000 and officials began calculating the damage to the economy from power and water problems affecting its key electronics industry.

Authorities called on Taiwan's citizens to contribute food and water to survivors and for caskets to help cope with mounting fatalities, which increased to 2,042 today, with 6,537 reported injured and 208 still missing.

The aftershocks, with preliminary magnitudes of 6.1 and 6.8 respectively, swayed major buildings and rattled nerves, but no casualties were reported. The earthquake that struck on Tuesday had a magnitude of 7.6.

Nearly two days after the quake, assistance remained just beyond reach for hundreds of thousands of people in the central counties of Taichung and Nantou, where the temblor struck hardest. Collapsed bridges, downed power lines and mangled roads still block relief from those who need it most.

Electricity was restored today to many buildings here in Taichung and in the capital of Taipei. But as night fell, huge sections of Taichung and Nantou counties were shrouded in darkness again. Power blackouts in some of the most badly damaged towns and villages--including Tungshi, Chungliao and Puli--thwarted efforts to provide anything more than rudimentary treatment for the most gravely injured. Sporadic phone contact with those areas made it difficult for doctors to assess the extent of victims' injuries.

"If they can get here, we can save them," said Chen Wei-kung, a trauma surgeon who runs the emergency room at China Medical Hospital in the city of Taichung.

For now, however, getting there is the problem. Chen, who arrived at his post within a few minutes of the initial tremor and has remained there without a break since, lamented tonight that there has been an inverse relationship between the speed at which victims stumbled through his doors and the severity of their injuries. First came the bruises, scrapes and gashes; then the compound fractures; then the severe head injuries.

Thus far, Chun has treated more than 300 patients, the vast majority of whom have come from central Taichung--an area that escaped major destruction from Tuesday's quake. Fearing a wave of serious trauma patients once the government reopens roads to quake-battered villages Thursday, Chen has put 200 doctors and paramedics on standby. But, he said, "I have no idea what to expect tomorrow."

Blocks away at the Taichung mortuary, the concerns are much the same. By hauling in two temporary refrigeration trailers and persuading local merchants to donate food freezers, the facility has managed to accommodate the 290 corpses that have arrived since Tuesday. But director Hong Chen-chi said the mortuary is quickly running out of space. "We can only take a hundred more," he fretted. "There isn't room."

An elite search-and-rescue team from Northern Virginia and Florida rescued its first survivor within minutes of arriving. Disaster experts from Fairfax County's Urban Search and Rescue Team and colleagues from a Miami team freed a 33-year-old man who had been trapped in a collapsed apartment building in the city of Touliu, the Associated Press reported.

Extracting others, however, could take days. And it could be weeks before electrical power, sewage and other basic services are fully restored. Taiwan's stock market, as well as many businesses and schools, will remain closed for a third day Thursday.

Although this earthquake was the strongest to hit Taiwan in three decades, jolts and tremors are not a novel phenomenon here. This island of 21 million people sits aside two of the most volatile plates that form the earth's crust.

In Taipei, which did not sustain heavy damage, city officials called on residents with trucks, buses or vans to pitch in Thursday at 7 a.m. to collect food, water and other supplies for residents in Taichung and Nantou. Moments after the announcement, nearly 100 volunteers had gathered in front of City Hall and had begun stacking supplies on a flatbed truck.

Taichung officials, meanwhile, are seeking more coffins and food freezers. At the mortuary this afternoon more than 100 stainless steel food freezers, most still bearing the logo or name of the donor firms, lay end-to-end in the parking lot. Each one contained a body, wrapped in a traditional yellow burial cloth. Friends and relatives hovered over the makeshift caskets this afternoon, weeping, uttering prayers and in many cases scrambling to ensure the coolers worked properly. Most freezers had been adorned with sticks of incense or ceremonial offerings of rice and fruit. Funeral ceremonies, arranged and funded by the local government, will begin Thursday morning.

The quake is also certain to take its toll on Taiwan's economy. The island is the world's third-largest maker of personal computer equipment and a crucial supplier of semiconductors to other industrialized nations; combined production amounts to $40 billion a year.

Any disruption in exports, as the Christmas shopping season gears up, would present a major problem for those industries. Most major chip factories are in the northern region of Hsinchu, where the quake did little damage.

But power outages and water disruptions have halted production, and executives of some large chip makers were quoted in the local media this morning as saying that it could take two weeks before they resumed operations. The prospect of reduced output from Taiwan pushed up chip prices around the world Tuesday and boosted stock prices of rival chip makers in South Korea.

There also were new concerns today that shoddy building practices may have added to the death toll in some areas. Government inspectors said they had found cause to launch a formal inquiry into alleged building violations at the 78-room Sungshan Hotel, one of three large buildings toppled in the Taipei area.

CAPTION: Rescue workers continue digging through debris in search of survivors in Nantou, Taiwan. However, more than two days after the quake, assistance remained just beyond reach for thousands in the counties of Taichung and Nantou, where the temblor struck hardest.