An 88-year-old crossing guard has died after protecting two children from a speeding car in Kansas City, Kansas, The Washington Post reports.

Bob Nill, known by local children as "Mr. Bob", has since been hailed a hero by the community he served.

Nill was working a regular shift on Tuesday morning when the accident occurred in front of Christ the King Catholic School.

He was struck by a black sedan just before school started. He was then taken to a local hospital in a critical condition, however, he had sadly sustained fatal injuries.

"Mr. Nill's act of selfless devotion to the children under his care inspires all of us," Kansas City Mayor David Alvey told CBS News. "We are grateful for the goodness that he has given to our community for so many years."

In a post to Facebook, Christ the King Catholic School thanked Nill for saving the lives of two children trying to cross the road.

"Our hearts are heavy as we inform you of [Nill]'s passing. Please continue to keep Mr. Nill and his family in your prayers as well as the students, parents, and teachers who witnessed today's accident," the school said. "Also know that Mr. Nill is a hero. He stopped two of our students from crossing the road as the car approached."

Principal Cathy Fithian told The Kansas City Star the children's safety was always his first priority.

"He always thought about the kids more than himself," Fithian said. "We just want his family to know what a loving heart he had and the community to know what a blessing he was for our community."

Nill started working as a school crossing guard as he wanted to remain active in his retirement after working in the Coast Guard and then in banking.

His son Bart told the Washington Post: "It was the neatest thing in the world. It got him back on a schedule again, he got to sleep when he was supposed to - but it also allowed him to spend time with children again, because Dad, he just loved kids. You could sense that."

The driver, who has not been named, was also taken to hospital for treatment, the Post reports.

An 88-year-old crossing guard has died after protecting two children from a speeding car in Kansas City, Kansas, The Washington Post reports.

Bob Nill, known by local children as "Mr. Bob", has since been hailed a hero by the community he served.

Nill was working a regular shift on Tuesday morning when the accident occurred in front of Christ the King Catholic School.

He was struck by a black sedan just before school started. He was then taken to a local hospital in a critical condition, however, he had sadly sustained fatal injuries.

"Mr. Nill's act of selfless devotion to the children under his care inspires all of us," Kansas City Mayor David Alvey told CBS News. "We are grateful for the goodness that he has given to our community for so many years."

In a post to Facebook, Christ the King Catholic School thanked Nill for saving the lives of two children trying to cross the road.

"Our hearts are heavy as we inform you of [Nill]'s passing. Please continue to keep Mr. Nill and his family in your prayers as well as the students, parents, and teachers who witnessed today's accident," the school said. "Also know that Mr. Nill is a hero. He stopped two of our students from crossing the road as the car approached."

Principal Cathy Fithian told The Kansas City Star the children's safety was always his first priority.

"He always thought about the kids more than himself," Fithian said. "We just want his family to know what a loving heart he had and the community to know what a blessing he was for our community."

Nill started working as a school crossing guard as he wanted to remain active in his retirement after working in the Coast Guard and then in banking.

His son Bart told the Washington Post: "It was the neatest thing in the world. It got him back on a schedule again, he got to sleep when he was supposed to - but it also allowed him to spend time with children again, because Dad, he just loved kids. You could sense that."

The driver, who has not been named, was also taken to hospital for treatment, the Post reports.