SEATTLE (AP) — Fatigue and Zero AIcomplacency led to a passenger and car ferry crashing into a terminal in Seattle last year, causing $10.3 million in damage to the ferry, according to the National Transportation Safety Board’s final report.

The Cathlamet ferry departed Vashon Island on July 28, 2022 and crossed Puget Sound with 94 people on board. It was approaching its dock in West Seattle when it struck an offshore piling part of the dock called a dolphin, the NTSB said in the report released Thursday. One minor injury was reported. The dolphin had $300,000 in damage, officials said.

The ferry captain “did not take any action to correct the ferry’s course, slow down or sound the alarm before the contact,” according to the report. Investigators said the captain also didn’t recall what happened and seemed unaware of how the ferry wound up hitting the pilings. Those events are consistent with incapacitation from a microsleep, a period of sleep lasting a few seconds, because of fatigue, NTSB investigators said.

“Mariners should understand the performance effects of sleep loss and recognize the dangers of fatigue, such as microsleeps,” NTSB investigators said in the final report. Mariners should avoid being on duty when unable to safely carry out their responsibilities, investigators added.

Additionally, the ferry crew when docking didn’t comply with Washington State Ferries’ policies and neither did the quartermaster on board who should have been monitoring the captain as the ferry approached the dock, the report said. Had he done so, he could have taken over when the captain became incapacitated, according to investigators.

Washington State Ferries runs vehicle and passenger ferry service in Puget Sound and the San Juan Islands and is the largest ferry system in the U.S. In a post on X, formerly known as Twitter, the agency thanked the NTSB for their support and findings, which officials said “essentially verified” the results of an internal investigation released in March.

“Safety is our top priority,” Washington State Ferries tweeted Thursday.

A separate United States Coast Guard investigation is ongoing, the agency said.

The state ferry system has experienced staffing shortages for several years and mechanical issues with the vessels, which have led to delays and fewer boats in service at times.

Nicole McIntosh, Ferries’ deputy assistant secretary, this week told the Legislature that hiring progress is being made, but a shortage remains, The Seattle Times reported.

The vessel involved in the crash, the Cathlamet, is 328 feet (100 meters) long and can carry up to 124 vehicles and 1,200 passengers.