Read the text below and answer the question. There's only one correct answer. One sunny afternoon, Bob decides to host a barbecue in his backyard. He invites friends over and sets up a large grill. As the party progresses, Bob becomes distracted while socializing with his guests. In his excitement, he accidentally spills hot charcoal from the grill onto Alice's lawn, causing a small fire that damages her flowerbed and lawn. Alice, upon discovering the damage, confronts Bob about the incident. Bob apologizes but claims it was an accident and that he did not intend to harm Alice's property. However, Alice is upset about the damage and the cost of replacing her flowers. Question: What caused the damage to Alice's property?