OKLAHOMA CITY - The Oklahoma Highway Patrol recently said farewell to its longest serving bomb-sniffing dog, Nitro. The 12-year-old German Shepherd died suddenly, right before his retirement, but he made a big impact on his team.

Nitro was set to retire this month, and his handler Lt. Mike Norman had already gotten his replacement, K-9 Bob. Now Bob has some big paws to fill.

Nitro was a 10-year veteran of the bomb squad and he was serious about his job. He helped protect President Obama, Olympians and plenty of Oklahomans.

Norman said, “This dog will stare at you, you’ll stare at the dog, and then you would hear him growl a little bit. It was kind of odd, but that was Nitro’s demeanor through his whole life.”

Norman said Nitro stood out not only because of his unique coloring, but also because of his extremely large size. Plus, he was tough. That is why Norman had no idea Nitro was in pain until it was too late.

He said, “I got the new dog. I’m down there doing the certification with him, when I get a call that Nitro can’t get up.”

He had been battling a urinary tract infection.

“I was really hoping that I’d get the call that he’d be fine,” Norman said. “4 o’clock in the morning the next morning he had passed away, so I wasn’t expecting that.”

Norman had hoped Nitro would be able to show Bob the ropes.

He said, “I had always planned on giving him that big T-bone on his retirement day, and he didn’t get it.”

Now Nitro’s memory will live on through a plaque inside the OHP Bomb Squad office, along with all the other bomb-sniffing dogs that came before him.

“Every time I walk down that hallway I see him, and I’ll never forget him,” Norman said.

But Norman is turning his attention to his new trainee, who still has a lot to learn.

“He has taken some of the pain away from losing Nitro because he’s such a fun dog,” Norman said of the one-and-a-half-year-old Bob. “He has such a good demeanor.”

Norman just hopes Bob can live up to his predecessor's legacy.

Of Nitro, Norman said, “He was a very good dog and I’m so proud to have worked him.”

The purchases of Bob and another young OHP K-9 were made possible through a donation by Express Personnel Services. All of OHP’s bomb-sniffing dogs are trained at Tarheel Canine in North Carolina.