Wolf Gruca remembers his family in Poland walking to the Nazi death-camp trains during World War II.

The separation of the young Jewish citizens from the old.

In the end, only he and one of his brothers in his family of eight survived the Holocaust.

"In the boxcar, just two days were terrible," the Troy man said Thursday — his 100th birthday — adding that in the labor and concentration camps, they "can kill you in a second."

But Gruca had a will. And a trade.

A trade the Germans wanted. A trade that probably saved his life. A trade that, years later, gave him a life and a job in Detroit.

"My story is not a five-minute story. I need at least a week," said the tool maker with a Polish accent, still proudly strong, with the English he learned after arriving in the United States in 1949. "I want someone to listen and understand. Not everybody listens."

Gruca shared some of his story before a birthday bash at American House Troy, where he has lived since the fall.

He remembers his public and Hebrew school teachers in Poland and his parents, three brothers and two sisters. He was born in Czestochowa, Poland, the south-central city where the Jasna Gora monastery houses the famous painting "Our Lady of Czestochowa," also known as The Black Madonna.

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According to his biography on the website of the Holocaust Memorial Center in Farmington Hills, one of his fondest memories was preparing and observing the Sabbath each week.

He also learned the trade of being a tool maker, work that he did before the war.

During the war, Gruca remembers being in the labor and concentration camps for three years — camps in Poland and Germany — wearing clothes that didn't keep him warm and eating thin pieces of bread.

Gruca remembers working long hours and at times, people being taken "and you never see the people no more." He also remembers when he eventually heard the words, "You are free."

From 1945 to 1949, Gruca was in a displaced persons camp. That's where he met his wife, Regina, in 1947. They married six weeks later.

With the help of the American Jewish Joint Distribution Committee, they made their way to Detroit in 1949.

Without a dime.

Without the English language.

With a small child.

"It's amazing. And you wonder about the strength and will to do that," said Gruca's daughter, Mary Starr of Troy. "Not having a relative here. Learning how to drive a car. He had to find work."

But her dad found the will to do so much.

Wolf Gruca said he became a U.S. citizen in 1954. He got hired at Chrysler, where he was a tool maker for three decades, working in Highland Park and Detroit.

He lived in Detroit until 1973 before moving to Southfield, his family said.

Wolf Gruca and his of wife of 53 years — their wedding anniversary also was Thursday — had three children; four grandchildren, including Rabbi Aaron Starr of Congregation Shaarey Zedek in Southfield, and four great-grandchildren.

His son, Joseph Gruca of West Bloomfield, said that he believes his parents survived the Holocaust because of their trades. His father, a tool and die maker; his mother, who was from Krakow, a seamstress.

"The Germans needed that," Joseph Gruca said.

There are an estimated 85,000 Holocaust survivors in the United States, said Noel Kepler, global communications strategist with Claims Conference in New York.

Holocaust exhibit

Portraits of Honor: Our Michigan Holocaust Survivors is an interactive exhibit of the Program for Holocaust Survivors and Families, a service of Jewish Senior Life of Metropolitan Detroit. It was developed in 1999 and is a permanent interactive exhibit at the Holocaust Memorial Center, 28123 Orchard Lake Road, Farmington Hills.

In the exhibit's initial opening in 2011, there were 401 Holocaust survivors featured. Three years later, an additional 147 survivors were added, with the goal of adding more photographs and biographies.

On Thursday, Wolf Gruca moved his leg to the sound of a live polka band. Without the use of his wheeled walker, he handed out full-size Hershey's milk chocolate bars to everyone at his birthday bash.

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"He has a great sense of humor and he has a zest for life for all that he has been through," said Gruca's daughter-in-law, Sandy Gruca of West Bloomfield. "He's always planning something."

Red and yellow balloons dotted the room as Gruca sliced his birthday cake.

A short time later, he pulled out an envelope from a seat compartment in his walker and spread out a handful of black and white photos of himself and his wife taken after the war.

When asked about the biggest highlight of his life, he had a simple answer.

"I'm alive today."

Contact Christina Hall: chall@freepress.com. Follow her on Twitter: @challreporter.