Plácido Domingo was rehearsing in Chicago last September when a friend phoned to say that there had been an earthquake in Mexico City, where many of the opera star's family and friends live. "I wasn't that concerned, at first, because there have been so many earthquakes in Mexico," Domingo recalls. But as evidence of the quake's devastation mounted, he became anxious. Anxiety turned to alarm by Sept. 21, when reports from friends indicated that, while his parents had survived the catastrophe, four of his relatives—his aunt, uncle, cousin and the cousin's infant son—were among the missing.

Twenty-four hours later, Domingo, 44, arrived at the site of his relatives' collapsed apartment building, where he joined in the hunt for survivors. Although some of the building's residents were found alive as long as a week after the quake, all of Domingo's missing relatives perished. To cope with his grief, and to help Mexico City residents devastated by the quake, he has begun giving a series of benefit concerts around the world. Domingo, who hopes to do a total of 20 programs, estimates that the two performances held so far—in Bari, Italy and Zurich—have raised $400,000. Tickets sold for up to $100. Four more concerts are scheduled for Europe in January, and he hopes to appear in the U.S. early this year. "I am Spanish but I have been connected with Mexico from the earliest part of my life," says Domingo, who moved with his family from Spain to Mexico City when he was 8. "My parents worked almost their entire careers there, my wife is Mexican and two of my three sons, José', 27, and Plácido Jr., 20, were born there. I feel especially close to those people at my relatives' building with whom I lived every day during the rescue."

Domingo talked with Rome correspondent Logan Bentley about his experiences in Mexico.

Initially I was told not to worry, that nothing had happened in the town where my parents live, which is about four miles from Mexico City. But I began to worry after watching the TV news. We saw what a disaster it was, and we still had no news from anyone there. Finally, that evening we were contacted by a television reporter from the north of Mexico who said that my mother had called, that they were okay, but that they didn't have any news about our relatives in the city. Two days later we got the message that four of them were listed as missing. My cousin's wife, Julia, was not among them. She had been found.

My mind was completely in Mexico. I tried to cancel my performance at the Lyric Opera that night, but it would have put the theater in enormous trouble. "The show must go on," as they say, but I felt terrible.

My wife Marta and I arrived in Mexico about 5:30 in the morning on Sept. 22. The first thing I did was call my sister, Maria José, who told me what happened to Julia. Julia and her husband, Agustin, had been in bed when they felt the earthquake. He told her to stay under the arch of the door while he went for the baby. The next moment everything collapsed. She was screaming for an hour. Though trapped, she could see a bit of sky, so she knew that she had a good chance. They found her an hour later. Just to give you an idea of the shape of things there, we were not able to find Agustin and their baby, Julio, who were just a few meters away, until eight days later.

When I arrived at my parents' house, I saw how desperate they, and especially my aunt, were. She felt she had lost everything. That's when I decided to go to the city to see what I could do.

The sight of my relatives' building will remain with me forever. It was a 13-story structure; they lived on the fourth and fifth floors. The back of the building had come forward and other floors had collapsed on top of my family's apartments like a stack of pancakes. They were still taking people out alive, so I thought, "Why not? We must have faith and maybe we will be among the lucky ones, too."

Suddenly, television crews and newspaper people realized I was there and wanted to interview me. At first I asked them to let me alone, but then I realized I could use the cameras to ask for assistance. I asked the engineers, the doctors and the people in charge of food distribution what they needed and I started making calls. Miguel Alemán Jr., the son of Mexico's former president, helped me enormously. The Mexican television network Televisa put cameras at my disposal anytime I wanted to ask for help. I saw the ABC cameras and made a direct appeal to President Reagan, asking for dogs trained to sniff for survivors. I don't know if there was any connection, but later the American ambassador, John Gavin, told me we could ask the American Embassy for anything we needed. They were fantastic. We also got cranes from Petróleos Mexicanos and the national railroad, and someone traveled all the way from Denver with a machine for cutting concrete.

We continued to dig at the remains of the building for more than a week. We had to wear masks because of the terrible stench from decaying bodies. Even after we began to fumigate, the odor was still strong at times and unhealthy. My hope grew on Sept. 24 when a 79-year-old friend of my parents was saved. The 26th turned out to be the last day that we found life. A married couple came out. The woman was unharmed, but the man lost an arm and hurt-one leg very badly. I began to lose hope that we would find my relatives alive. All I could hope for now was that, when we found them, there would be some way to prove that they died quickly and didn't suffer.

From all indications, that is what happened. On the 27th we found my cousin and 10 hours later, the baby. The roof had collapsed on them. We found my aunt and uncle, Juan and Paquita, the next day. I was present when everybody was found. Everybody in our family just tried to hold each other up. My wife Marta gave me immense support when I came home exhausted every night. My son Jose had arrived three days before and he was the one I could be weak with. I felt such great despair. The days before had been filled with ups and downs, hope, despair, hope, despair.

I became very close with the other families of the missing, who at first were afraid that once I found my relatives I would leave. I stretched it to the last moment, but on Oct. 4 I had to go to Rome to work on a film that was already in progress. But I made up my mind that even though I couldn't be there, I would find some way to continue helping.

That was why I came up with the idea of doing concerts for Mexico. My relatives tell me that the economy is not good but that people are starting to rebuild and it will take a very long time. I want to channel the money from the benefit concerts directly to the families—there are 180 of them—in my relatives' compound. Some have lost their homes, their jobs, the heads of their families. I asked myself what I can do. There is no way to bring back what those people have lost. I can try to help them rebuild their lives.