HONOLULU (AP) — The National Transportation Safety Board released an investigation report Wednesday on a fatal Hawaii tour helicopter crash that killed seven people.

The report with more than 1,300 pages said an unusual weather pattern was present in the area on the day of the crash and witnesses reported low visibility with fog and rain. Rescue efforts were hindered because of weather.

Wednesday's report did not detail a cause for the crash. A report with final conclusions will be released at a later date.

The Safari Helicopters tour of Kauai’s remote Na Pali Coast crashed on a steep, forested slope on Dec. 26, 2019. There were no survivors.

The pilot, 69-year-old Paul Matero, had his license revoked in 2010 after testing positive for marijuana. His certificate was fully reinstated in 2012 after completing required programs.

Matero was well regarded by passengers, colleagues and aviation officials, the report said.

A toxicology report after the crash found no drugs in Matero's system.