I need more information regarding your brother's accident in order to properly answer your question. He could have various claims against different parties. First of all, your brother can file a worker's compensation claim.
He may also have third party liability claims against other parties. Was there fall protection to prevent your brother from falling? For example, was he wearing a safety harness that malfunctioned? If that was the case, then he may have a case against the safety harness manufacturer.
If his accident happened in New Jersey, he may be able to bring a case against his employer if his employer committed an “intentional wrong.” This is where an employer knows the consequences of an act are substantially certain to result in harm to a worker.
For example, if your brother's employer told him to take off the safety harness when he should have worn it while on the roof, he may be able to bring a claim against the employer.
There could be multiple parties responsible for your brother's injuries depending on who else was at the construction site and what responsibilities these parties' had at the time of the accident.
Different facts would lead to different theories of liability against the responsible parties; therefore, it is important that you speak to an experienced construction accident lawyer to investigate your brother's accident. Feel free to call me or my colleagues at 877.944.8396 to discuss your brother's fall accident.