(CNN)Cooper Wallweber set up his lemonade stand on a warm Thursday afternoon near St Louis. The 5-year-old had no marketing plan; just a goal to help a first responder in need. By the end of business, the young entrepreneur had raised more than $3,000 for a wounded volunteer firefighter.
A 5-year-old boy raised more than $3,000 to help cover a wounded volunteer firefighter's medical bill
"Skateboarders stopped by!" the proud proprietor told CNN. "Firetrucks and the ambulance!"
Cooper, with help from his big sister, set up shop in front of an elementary school near the family's home for just one day and immediately got traction when word spread that the proceeds would go to a local volunteer firefighter named Arlydia Bufford.
"I posted like 10 o'clock at night, just on my Facebook page, and then it got started," Wallweber's sister, Olivia Boyer, said.
On June 22, Bufford was shot while dining with colleagues at a neighborhood Applebee's. The team had just completed an EMT training class.
Kinloch Fire Lt. Mark Fantroy said the gunman entered the restaurant and opened fire.
"He was eating dinner inside, then went outside, got a gun, came back and shot two other people, and then turned the gun on her."
Bufford was shot in the head. One of the firefighters she was with, Capt. Darion Meeks, sprang into action.
"He actually helped push her down and shield her," Fantroy told CNN. "He also provided lifesaving medical care while she was transported to the hospital in the back of a police Tahoe. Without him and the first arriving officers realizing the critical nature of the injuries we would be having a different conversation today."
One woman was killed and another woman suffered non-life-threatening injuries.
"She worked as a waitress as her full-time job," Fantroy said of Bufford. "And she did not have health insurance."
But the community rallied, raising funds to help cover the firefighter's hefty medical expenses. And young Wallweber played his part.
Cooper received a gift basket from his teacher for successfully completing Pre-K. The basket included a 5-year-old's dream toy -- slime.
"Cooper decided to put the slime in his shoes, and it ruined them," Boyer, his big sister, said. "We were just going to do a lemonade stand to raise money for new shoes just to show him different ways of working and earning things and teaching financial responsibility. But as soon as we found out about Arlydia on the news, that all changed."
And the more they learned about the 20-year-old firefighter, the more they felt connected to her.
"She graduated from East High School and that's where our parents graduated from," Boyer shared. "She was a softball player and I played college softball."
"It was divine intervention," Michelle Wallweber, their mother, said.
For his fundraising, Cooper was sworn in as an honorary firefighter by the Kinloch Fire Protection District.
Bufford has been a firefighter for six months and had responded to at least three calls, according to Kinloch Protection Fire Department. She was also training to become an EMT.
"She was supposed to go to college on a softball scholarship, but she chose to be a firefighter," her mother, Rebecca Bufford, told CNN. "She puts her all into everything she does and will give you the shirt off her back."
And while Bufford has support from family, friends and the community in the Gateway City, she has a long recovery ahead.
"She's talking a little bit, but not much. She's stable and in critical condition," the firefighter's mother said.
Bufford says the outpouring of support is overwhelming, and she's quite impressed by 5-year-old Cooper.
"You know, I wouldn't expect that from a 5-year-old. His parents and family have taught him very well."
The families planned to meet for the first time Wednesday night at a fundraiser for Bufford.