Standing on a pile of debris that is all that is left of the marketplace of Zimnicea, Mayor Dumitru Sandu announced proudly that a new town will rise out of the rubble within two years.

Zimnicea, a river port of 20,000 people on the banks of the Danube, was almost completely destroyed in the earthquake that his Romania March 4. Four out of every five houses in the town, including most of the principal buildings, collapsed or were so severely damaged that they must be pulled down.

Although many more people were killed in Bucharest than the five killed here and much greater economic losses were suffered in he industrial cities of Graiova and Ploesti, no other town in Romania suffered as much damage in proportion to its size as did Zimnicea.

Now that most of the rubble has been cleared away, the town center looks like a flattened building site. Shops have been replaced by mobile canteens and brick houses by temporary wooden huts.

Since the disaster, Zimnicea has twice been visited by President Nicolae Ceausescu, who has promised that 3,000 new apartments will be built here within the next two years. He told reporters at a press conference in Bucharest last week that a team of designers would choose materials that could withstand future earthquakes.

Responsible for the town's reconstruction will be Sandu, 37, who, ironically, was installed as mayor only moments before the town's destruction. A packed meeting of 400 people in the town's House of Culture had just elected him mayor when there was a violent tremor and the whole building began to shake.

"As the tremors grew in intensity. I found I couldn't stand on my feet any more and was thrown to the ground. It was as though the earth was cracking. Then a dreadful whistling noice filled the room," he recalls.

Everybody rushed for the doors. Fortunately the House of Culture, a huge pink edifice, did not collapse although it has gaping holes in the walls and must be demolished.

In the streets, people trapped in damaged buildings were crying for help. Terrified that there might be another earthquake, the entire population of Zimnicea spent the night out in the open huddled around fires.

It is uncertain why Zimnicea, which is the southermost town in Romanis, on the Bulgarian border, should have been so severely hit when it was much farther from the epicenter of the quake than many other cities that escaped with relatively little damage.

On theory is that the shock waves reached a peak beneath Zimnicea after rebounding from the hills that rise up beyond the town. Another is that the extremely soft soil due to annual flooding from the Danube did not provide protection against the tremors.

"I have lived through floods, earthquakes, droughts, everything - but nothing has ever been as bad as this," said Alexandru Bacica, 83, who was busy clearing away the rubble, brick-by-brick, from an Orthodox church just outside Zimnicea.

His friend, Jordan Trifu, 74, described what happened when the earthquake struck.

"I was in bed next door to the church when I was awakened by the noice. I rushed out and saw the gold bowls that contain incense swaying from side to side. Then that central onion dome up there crashed down onto the stone floor."

In the town itself, the damage was equally severe. The director of the hospital, Dr. Ion Gherghiceaniu, had been at the election meeting in the House of Culture. He ran back to his hospital to find everything in chaos.

"It was terrible. All the patients had run out into the street in their pajamas and nightdresses as they were frightened that the building would fall down. People who had been injured were being brought to the hospital but there was nowhere we could put them," he said.

Since most houses in Zimnicea are one-story buildings, casualties were relatively light. Five persons were killed and 159 injured were taken to hospital.

The hospital did not collapse but now is in such a weekened state that it will have to be razed.

Soldiers and Communist Party officials have been drafted into Zimnicea from other parts of Romania to help in the reconstruction. The homeless have either gone to stay with relatives or are being housed in prefabricated huts that are springing up around the town.

The town's textile and handicrafts factories, the basis of its economy, lost a good deal of plant and equipment in the disaster. To make up for loss of production. The government has postponed plans to cut the work week from 48 hours to 42.

"We had hoped that we would be able to work a five-day week by the end of this year, but that is now totally out of the question," said factory chairman.

The people of Zimnicea have made a good start at clearing up the mess left behind by the earthquake but long-term reconstruction will be more difficult - and for some people the promises of apartments and television sets will never make up for what they have lost.

Dressed in a rumpled blue suit that he managed to retrieve from the runs, Stancu Ciobanu, 50, looks through a fallen wall at the remains of the ornate brick villa that has been the property of his family for generations. After years of careful upkeep, it is now little more than a heap of rubble waiting to be pushed away by a bulldozer.

"When I told my son in Bucharest what had happened to our home, he was very sad. Perhaps we'll get a flat, but it'll never be like this," he said.