One of the people involved in the accident is currently in fair condition at UNC Hospitals Jaycee Burn center.
The island held a memorial parade on Sunday to honor and memorialize the four victims that lost their lives.
Two volunteer firemen were treated for inhalation and exhaustion while trying to clean up the scene.
Hyde County spokeswoman Jamie Tunnel said the parade also paid tribute to volunteers, local and state response crews that helped after a truck carrying fireworks exploded on the Ocracoke Island docks.
Ocracoke Island is the southernmost inhabited island on the Outer Banks, about two hours from the mainland.
The island is only reachable by ferry. Ferry service to the island was suspended to public travel and limited to emergency personnel after the accident. The Hatteras Island ferry was also temporarily suspended and later reopened.
Saturday's incident is not the first time Melrose South Pyrotechnics has been involved in a deadly accident.
The company's facility in Landsford, South Carolina exploded in July of 2001.
One person was killed and two others were hurt.
South Carolina Occupational Safety and Health Administration issued the company with several fines for the incident. It was given 10 citations total, with nine of them classified as serious.