WASHINGTON -- The reasons to run a marathon are as varied as the runners.

But, for Elizabeth Ottaway of Alexandria, who's running the SunTrust National Marathon for the second year in a row, the path of the race course provided the motivation.

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That's because it goes right by Children's Hospital, the place that was her infant son's only home.

It was Sept. 16, 2003, when her son Alexander was born two months early.

Children's Hospital's neonatal intensive care unit became his home.

For five months, Elizabeth, her husband John and the doctors and nurses forged a bond as they endured highs and lows of repeated surgeries.

But on Feb. 25, Alexander died.

"My running friends were amazing," said Ottaway. "When Alexander died, they were right there encouraging me to come back and run again. For me, it had been such a part of my life before Alexander, I was able to use running to bring some sense of normalcy back into my life again and begin routines over again."

When Ottaway saw the National Marathon's race course and noticed it went by the hospital, she decided to run it in honor of Alexander and the NICU team at Children's Hospital.

"Running in Alexander's honor gave me a strength running that I had never had before," she said. "It was emotional, but a positive emotion."

In the pocket of her running shorts during her last National Marathon, Elizabeth carried a picture of Alexander.

At around mile 21, when Elizabeth passed Children's Hospital, she got a big boost from the NICU nurses and staffers who were down on the street, holding signs and shouting her name.

That wasn't all -- another one of Alexander's nurses was waiting at the finish line.

They'll be back out again in force this year, too.