(Updated at 4:55 p.m.) Carl Diener was a fitness nut — a big, strong man who, having retired from the federal government, decided to apply his love of exercise by working part-time at two local fitness facilities.

When employees at one of those facilities — the YMCA Arlington Tennis & Squash Center at 3400 N. 13th Street — first heard yesterday that two men had finally been arrested for Carl’s 2009 murder, at least one woman burst into tears.

“We’ve all been sort of waiting around and hoping [police] find who did it,” said Audrey Giberman, who works at the Tennis Center and who formed a close bond with Carl through the years. “He’s always been on our mind. It was a horrible, horrible tragedy.”

Giberman recounted vivid memories of the morning when Carl, a Lyon Village resident, did not show up to work as usual.

“The morning he didn’t show up, Sport and Health (Diener’s other fitness center employer) called me and said… ‘Carl’s not here.’ My front desk started calling all the hospitals. A Sport and Health member actually went to Carl’s apartment,” Giberman remembered. “When it was officially announced by police… it was very hard. Actually some of the staff went for counseling, it was such a shock.”

Now, Giberman and others are hoping that the arrests will help shed light on those lingering, unanswered questions surrounding the murder.

“You hear all these things, and you just want to know why,” she said. “You just want closure.”

Police have identified the two suspects arrested for Carl’s murder as Roger K. Clark III (top), 20, of Severn, Maryland, and Javon Martin (bottom), 24, of Washington D.C. Both men are now being held in the Arlington County Detention Center. So far, authorities have not revealed a motive in the case.