Simplify the following text for a Grade 11 native English-speaking person.
Original: In 1967 Horton partnered with investor Ron Joyce , who assumed control over operations after Tim Horton died in a car crash in 1974 , and expanded the chain into a multi-million dollar franchise .
Simplified: In 1967 Tim Horton joined with investor Ron Joyce , who quickly took over running the company and expanded the chain into a multi-million dollar franchise .