PHILADELPHIA (CBS) — It started with one lemonade stand filling glasses – but it’s since become the cause so many pour their hearts into.

“When someone in your community goes through something like that, the whole community feels it.”

On a frigid Sunday morning, thousands of runners and walkers hit the ground in Fairmount Park for the ninth annual Lemon Run – a fundraiser for childhood cancer research, organized by Alex’s Lemonade Stand.

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The foundation honors the life of Alex Scott, an 8-year-old girl who lost her battle with neuroblastoma in August 2004.

“It’s a bitter-sweet day, but there are so many childhood cancer families here that this event especially feels so upbeat to me and so positive to me, and there so many reasons to celebrate with all of the survivors that are here,” said Liz Scott, Alex’s mother. “There’s still a long way to go, but we’ve made so much progress. I feel so hopeful. I feel so proud to know that if Alex was diagnosed today, things might be different for her.”

The event celebrated survivors and honored those who have passed.

Maddie Davis of Newtown Square lost her best friend, 11-year-old Hailey Parker, to childhood cancer in October 2015.

“I want them to know that Hailey did her best to fight,” Davis said, “and she made every single one of us proud.”

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She ran the 5K in Hailey’s loving memory as part of the team ‘Fight Like Hail’ – and says she’s grateful for the community’s support.

“It makes me super happy,” Davis said. “I can’t believe so many people want to help stop childhood cancer and it’s incredible.”

Ten-year-old Connor wanted to support his friend Cole, a cancer survivor.

“We talk a lot and we go to the same karate school,” Connor said. “He’s actually not supposed to run in my run but he’s still going to run with me even though he’s having some leg problems.”

All money raised is dedicated to pediatric cancer research and to improving the quality of life and care for patients and their families.