The airline employee who stole a plane for an “unauthorized flight” at Seattle-Tacoma International Airport on Friday before crashing was able to “legitimately” access the area where the craft was held, officials said in a news conference on Saturday. They said they think he was the only person aboard.

“All of us at Alaska and Horizon are deeply saddened by last night’s unauthorized flight with the Horizon Q400 aircraft that resulted in the loss of life for the individual involved,” said Brad Tilden, chief executive of Alaska Airlines. “All 23,000 of us want to express our sincere sympathy to his family, his loved ones and his co-workers.”

At the news conference, officials with the FBI, Alaska Airlines, Horizon Air and the airport (SeaTac) offered an update on how they think events unfolded.

While refraining from confirming reports of the worker's identity, officials said he was a ground service agent for Horizon Air and had been employed there for more than three years. Horizon is a subsidiary of Alaska Airlines. He had undergone numerous background checks and “was fully credentialed,” officials said.

The man involved was identified as Richard Russell, a U.S. official briefed on the matter told the Associated Press. The official wasn't authorized to discuss the matter and spoke on the condition of anonymity.

‘SUICIDAL’ AIRLINE EMPLOYEE WHO STOLE PLANE FROM SEATAC AIRPORT HAD BIZARRE CONVERSATION WITH AIR TRAFFIC CONTROL BEFORE CRASHING

“He had access to that area legitimately,” said Mike Ehl, director of operations at SeaTac. “It is inside the security fence, and so no security violations were committed.”

Prior to the episode, which began around 7:30 p.m. local time, the Q400 aircraft was removed “from a maintenance position and was not scheduled for passenger flight,” an official said. There is no indication that the worker had a pilot’s license, and officials aren’t sure how “he achieved the experience that he did.”

The man appears to have been the only person on the plane, an FBI official said, adding that this hadn't yet been “confirmed that at the crash site.”

The FBI is leading the investigation, officials said.

PLANE CRASHES AFTER ‘UNAUTHORIZED TAKE-OFF’ FROM SEATAC AIRPORT, OFFICIALS SAY

“Safety is our No. 1 goal. There is nothing more important to us,” Tilden emphasized. “Last night’s event is going to push us to learn what we can from this tragedy so that we can ensure this does not happen again at Alaska Air group or at any other airline.”

The Horizon Air, 76-seat turboprop plane crashed on Ketron Island, southwest of Tacoma, Wash. There was no connection to terrorism, authorities said.

“An airline employee conducted an unauthorized takeoff without passengers at Sea-Tac; aircraft has crashed in south Puget Sound. Normal operations at Sea-Tac Airport have resumed,” said an airport tweet.

Roughly 75 flights were delayed over the situation, nine were diverted to other airports and five were canceled; more than a dozen had more than two-hour delays, Ehl said at the news conference.

The man who flew the plane was described as a 29-year-old “suicidal male” who “acted alone,” according to the Pierco County Sheriff’s Office.

Fox News’ Kathleen Joyce, Bradford Betz and The Associated Press contributed to this report.