Prime contractors are responsible for an entire project and engage directly with property owners. They also assume responsibility for any work that they assign to sub-contractors, and have exclusive control over the work quality, payment, and other responsibilities concerning said sub-contractors.
Put more simply, prime contractors have as much responsibility for their segment of the construction job as they do for the job in general, including whatever work they have subcontracted. This includes following safety protocol, hiring or subcontracting responsible individuals, and warning workers of potential hazards. Workers injured under the supervision of a prime contractor may be able to file a construction accident lawsuit against him or her for damages.