Scott Smith was about 10 years old when he and his big brother, Skip, found a dusty trunk in their Northfield attic.

The trunk had roller skates so old they had wooden wheels. It had pictures of a young woman the boys didn’t know, but some pictures showed that girl with famous people they did recognize, including W.C. Fields, the comedy and movie legend.

So the brothers took their treasure chest to their mom, Hazel. And they were shocked to learn that the girl was her, their mom, back when she was Hazel Roop, an Iowa girl who became an original star of a new, hot sport in 1930s America — roller derby.

Well before her funeral last month, at 98, Hazel Smith had her quiet life in Northfield interrupted by her roller-derby history. She was inducted into the National Roller Derby Hall of Fame in 2010, two years after she was honored with a Roller Derby Pioneer Award.

But that skating life ended after World War II started, and Hazel had basically kept it to herself until her boys found that old trunk in the ’60s.

“She didn’t want to brag,” says Scott Smith, now 62, of Dennis Township. “She was real low-key.”

Hazel got to Northfield because of the war. She joined the Women’s Army Corps, and was promoted to sergeant. Along the way, she met another sergeant, George Smith, a carpenter from South Jersey.

George and Hazel got married in 1946, and built a home in Northfield. They had three boys — Skip is 66 now and Gregory died at 55 in 2009.

Sometimes the boys watched roller derby on TV after they found out who their mom was.

“But she wouldn’t watch it ... because it was so phony,” said Skip, of Northfield. “She said it was nothing like when she did it. Then, it was like women playing football” — on skates. “You kicked butt, period.”

Hazel got so used to the bruises and broken bones that she became her family’s favorite nurse. Skip’s wife, Debbie, said their son, Chris, is 25 now, but he still talks about the joys of a “MomMom rub” — Hazel’s back-rubs coaxed him to sleep as a kid.

Or Hazel would visit her son’s home — and end up massaging her daughter-in-law’s feet.

“Now come on — who does that?” Debbie said.

Her family has more stories of what a natural nurturer she was. And a few years ago, they found out Hazel was also very good at keeping a secret.

After the Roller Derby Hall of Fame found her in 2008, Hazel got a phone call from her past. The caller was Bill Bogash Jr., her oldest son — born in 1942, in Hazel’s pre-war marriage with another roller-derby pioneer.

The Smiths of Northfield never knew about another brother. But they have since become family to each other, after Hazel and her first son were reunited before she died.

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