Treelore is Aibileen's son who died a little over two years before the novel opens. He was only 24 years old at that time. The way Treelore died is important. Aibileen remembers,
One night he working late at the Scanlon-Taylor Mill, lugging two-by-fours, splinters slicing all the way through the glove. He too small for that kind of work, too skinny, but he needed that job. He was tired. It was raining. He slip off the loading dock, fell down on the drive. Tractor trailer didn't see him and crushed his lungs fore he could move. By the time I found out, he was dead. (1.9)
Aibileen's memory shows us that Treelore – a thoughtful, intelligent young man who's writing a book about his experiences in Mississippi – dies senselessly. This is largely because Treelore, and most of the other black men in Jackson, only have access to the most dangerous, most physically demanding, lowest-paying jobs.
For Treelore and men like him, there are no rules, laws, or social conventions to protect him on the job. His death was totally (tragically) preventable. But, as the passage subtly illustrates, Treelore was considered disposable, and nobody considered his safety important.
From Aibileen's perspective as Treelore's mother, her son's death is a most poignant example of how little appreciation is shown toward the black workforce in her town. Hearing about Treelore's death, and learning that he was writing a book about his life, gives Skeeter the idea for the book that ultimately becomes Help.