(CNN) Former Secretary of State Colin Powell wrote on Thursday about receiving help changing his tire from a veteran who lost his leg in Afghanistan, writing that it "touched my soul."

Powell, who's also a former chairman of the Joint Chiefs of Staff, wrote on Facebook that he had been on his way to Walter Reed National Military Medical Center, driving along Interstate 495, when his left front tire blew out.

"I am a car guy and knew I could change it but it was cold outside and the lug bolts were very tight," Powell writes. "I jacked the car up and got several of the bolts removed when a car suddenly pulled up in front of me."

While talking to the man who had pulled over to help, Powell wrote he learned the man had lost his leg in Afghanistan. The man told Powell he had recognized him and wanted to help.

"He grabbed the lug wrench and finished the job as I put the tools away," Powell writes, and then they both headed off to appointments at Walter Reed.

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