A 5-year-old boy raised more than $3,000 to help cover a wounded volunteer firefighter's medical bill

Five-year-old Cooper Wallweber set up his lemonade stand at an elementary school near St. Louis.

(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.

"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.
    Cooper Wellweber, 5, and his sister Olivia Boyer raised more than $3,000 that will go towards Arlydia Bufford's medical expenses.
    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.
    Volunteer firefighter Arlydia Bufford was shot in the head while out for dinner with coworkers on June 22.
    "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.

    What started as a way to pay f