Ken Hendricks, founder of ABC Supply Co. Inc. in Beloit, died early Friday after suffering a massive head injury in a fall at a construction site at his Rock County home.

The 66-year-old Hendricks, who also served as chairman and CEO of ABC Supply, died while in surgery at a hospital in Rockford, Ill.

Hendricks, who grew up the son of a roofer in Janesville, began shingling roofs on weekends while working two other jobs and by age 30 had 500 roofers working for him. In 1982, he acquired three roofing supply centers, which were the first locations of the new American Builders and Contractors Supply.

Today, ABC Supply is the nation's largest wholesale distributor of roofing with sales of nearly $3 billion. The company employs 6,000 people at 390 locations in 46 states and the District of Columbia.

Hendricks also owned or held controlling interest in, or held active board and management positions, with other companies, including American Aluminum Extrusion Co., Hendricks Development Group and Gem Pharmaceuticals LLC.

He is survived by his wife, Diane, their seven children and their families.