Siegfried Sanders celebrated his 99th birthday yesterday, but his eyes still twinkle with boyish glee when he recalls a friendship from his German youth.

The sparkle emanates from memories of three inseparable pals — one Protestant, one Catholic and one Jewish — and how their bond defied an era of unspeakable religious hatred.

Sanders, the Jewish member of the trio, is the last survivor — an unlikely scenario given that he was arrested and packed off to Dachau the day after Kristallnacht in November 1938.

"We were together all the time until the last minute," says Sanders of his ties to Paul Kauwertz, the Protestant friend, and Eugene Kuppers, the Catholic. Kuppers perished after being forced to join the German army; Kauwertz died in Germany in 1975.

The story of their friendship in the little town of Kaldenkirchen was documented in a 1999 book by Kauwertz's son, Frank. Written in German, the 455-page work is called "Die drei Eisheilgen," which means "The Three Holy Men." Frank Kauwertz, who was planning to visit Sanders for his birthday, hopes to get the book translated into English.

The book's cover has a photo of the three friends in their mid-20s, clad in swimsuits and standing in a rowboat floating on a pastoral-looking lake near their home.

"We were always together," says Sanders, who now lives with his 80-year-old wife, Ilse, in a high-rise apartment near Oakland's Lake Merritt. Sanders wears a hearing aid and thick glasses and uses a walker to help him get around. But his face is remarkably unwrinkled and his memory of his younger days remains crisp.

Sanders clearly remembers how his friends continued to stand by him in the face of the growing Nazi threat. And when Sanders got a visa that enabled him to leave Dachau after a short stay and flee to Haiti, Kauwertz sent him money that helped him as he struggled to start a new life.

"I had nothing," says Sanders, who still speaks with the accent of his native country. "We had to leave Germany with $4.

"I tell you something, you can't imagine what a good character he was."

After Sanders and his wife moved to Oakland in 1947, Kauwertz visited the couple annually. Kauwertz, a widower, joined them on cruises and trips to Las Vegas. The friendship lasted until Kauwertz's death.

"When I think about my friendship, I feel very good," says Sanders. "It was a wonderful friendship, open and good."

But his emotions turn chilly when he thinks of how so many Germans permitted the genocide to take place. "I can't understand the people. It's unbelievable," says Sanders, "that the church, everybody else, was quiet. It was unbelievable."

Reflecting back on his youth, Sanders said he and his two friends grew up in the same neighborhood. Their friendship began in 1906, when Sanders was 3 and his father, a butcher, built a home and slaughterhouse near the Kauwertz family.

When he was 20, Sanders opened a successful business as a men's clothier. The windows of that shop were smashed on Kristallnacht and when Sanders went to survey the damage the next day, the Gestapo greeted him. "They said, 'Are you Mr. Sanders?' They said, 'You are arrested,'" recalled Sanders. "I said, 'For what?' They said, 'You are arrested.'"

Sanders was packed into a cattle car with other prisoners for the five-hour trip to Dachau. "You hardly could breathe," he said. "We stood there for the whole night."

Once in Dachau, Sanders was awakened at 5 or 6 a.m. each morning and forced to march for most of the day. "It was bitter cold," he said. "It was in the wintertime."

On Dec. 24, 1938, Sanders was released after a cousin in Belgium secured a visa enabling him, Ilse and her family to go to Haiti. Sanders said he was one of the last Jews released from Dachau. "Then nobody came out," he said.

In July 1939, he and Ilse, who was his fiancée at the time, sailed to Haiti with Ilse's parents and brother. "We didn't know where we were going," said Ilse Sanders, whose father had run a prosperous sausage factory in Dusseldorf.

After settling in Port-au-Prince, Sanders opened a grocery store while Ilse made 10 cents per customer as a manicurist.

Kauwertz "sent me the first money," said Sanders of the $50 he received from his friend. Starting off was tough for the young couple, who didn't speak French or Creole and weren't accustomed to the humid climate of the West Indies.

Married in 1942, the couple moved five years later to Oakland where Ilse had a cousin. "When we came over here, we had to start all over again," recalls Ilse, who said they spoke no English when they arrived.

They ran a grocery store on Claremont Avenue until 1960, when Sanders retired and the building was demolished to make way for the construction of Highway 24. Ilse Sanders worked at the now-closed I. Magnin department store on Broadway until her retirement in 1991.

Sitting in a lounge chair in front of a big window overlooking their Oakland neighborhood, Sanders reflects on his 99th birthday and admits, "I'd like to be 20 again — but not go through the same thing I went through."