Neighbors remembered Hayes Sunday as a man who cared about his community.
"To have this type of hideous crime by such a mentally defunct person, it really has set me back," said Willy Ray, a friend of the victim.
Investigators say it was Tuesday when police found Hayes screaming for help in front of his apartment building near 63rd Street and Ellis. Officers say the man had answered an early morning knock on his door, and a former tenant doused him with gasoline and set him on fire.
Hayes had reportedly told a relative about problems he was having at his property.
Detectives say other building tenants called 911 after seeing smoke come from the landlord's first-floor apartment. Police say Hardy turned himself in.
"He believed in honesty, that people should respect the building that he owned, 'Pay your rent, I'll provide you with the hot water, services, etc.' He was a fair guy," said Leon Finney of the Woodlawn Community Organization, of which Hayes was a committed member.
Finney said whatever wrong Harlan Hayes saw, he would seek to right it.
"He sought to give and was always there to give of himself whenever required," said Finney. "He was a man to be counted on, and he stood his ground firm and sought the best for his neighborhood, and he's going to be missed."
As a result of the attack, Harlan Hayes was burned on more than 90 percent of his body.
Investigators said the alleged attacker remained in custody Sunday night.
The Associated Press contributed to this report.