A look at facts, lingering questions in Alaska plane crash

Days after a deadly plane crash in the heart of Alaska's largest city, there are lingering questions regarding what caused the pilot to fly into two office buildings, including one where his wife works.

The FBI is leading the investigation into the Tuesday morning wreck that killed 42-year-old pilot Doug Demarest, but has released little information. It declined to comment on any possible link involving the law firm where Demarest's wife is employed as an attorney.

Here's a closer look at what's known about the crash and what remains unknown or undisclosed by investigators:

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This Dec. 29, 2015 photo shows damage to the corner of The Brady Building after a small plane crashed into it in downtown Anchorage, Alaska. The pilot was not authorized to fly the aircraft used in volunteer search-and-rescue missions, authorities said. (Bob Hallinen/Alaska Dispatch News via AP) KTUU-TV OUT; KTVA-TV OUT; THE MAT-SU VALLEY FRONTIERSMAN OUT

WHAT HAPPENED?

Demarest was flying a Cessna 172 owned by the Civil Air Patrol when it clipped the building that houses law firm Dorsey & Whitney and smashed into the side of an unoccupied commercial building. No one else was hurt.

The crash occurred when most area businesses were still closed. It damaged a transformer and started a fire, which firefighters quickly extinguished. The buildings sustained only cosmetic damage.

The wreck happened in windy conditions, but investigators weren't ruling out anything as a cause, said Clint Johnson, Alaska region chief for the National Transportation Safety Board.

HOW DID THE PILOT GAIN ACCESS TO THE PLANE?

Demarest was a licensed pilot and a member of the Civil Air Patrol, a civilian auxiliary of the U.S. Air Force that helps with search and rescue, disaster relief and homeland security across the U.S.

The organization has said the flight was unauthorized, but a spokeswoman declined to say why.

The Cessna was housed in a Civil Air Patrol hangar at Merrill Field, a small airport on the edge of downtown Anchorage.

Airfield manager Paul Bowers said the airport's tower is staffed between 7 a.m. and 10 a.m. during the winter. The crash occurred at 6:18 a.m. Tuesday, but no one at Merrill Field saw it taking off that Bowers knew of. Towers at many smaller airports in the U.S. are similarly staffed.

The airfield itself is open 24 hours. Bowers said local Civil Air Patrol officials were alerted that morning after maintenance crews found the hangar door open. There was no sign of forced entry.

The workers did not note whether the plane was missing, he said.

Pilots can use their radios to share runway and other logistical information. But such announcements are voluntary and not recorded at the airfield, Bowers said.

IS THERE A CONNECTION BETWEEN THE CRASH AND THE PILOT'S WIFE?

Authorities have declined to say. The FBI released a statement Wednesday noting agency policy prevents it from commenting on an active investigation, including "confirming or denying reports surrounding this case other than to reiterate there is no indication this was a terrorist act."

Demarest's wife, Katherine Demarest, has not commented on the crash.

Bryn Vaaler, an attorney and chief marketing officer at Dorsey & Whitney's Minneapolis headquarters, has said no one was in the firm's Anchorage offices at the time of the crash. He had no information about the couple's marital status.

Doug Demarest's former stepfather Charlie Ballentine, meanwhile, described him as an outdoorsman and a good father. Asked about his thoughts on the plane striking the building where Katherine Demarest works, Ballentine said: "He was always a very levelheaded guy."

WAS THE FLIGHT ON ANY AVIATION RADAR?

The Cessna was seen as a blip on the radar for departure and arrivals at the Ted Stevens Anchorage International Airport several miles away, according to an official close to the investigation who was not authorized to publicly discuss the case and spoke on condition of anonymity. That radar can pick up even aircraft flying fairly low.

The plane was among four on the radar, but it wouldn't have raised any red flags unless it was close to another plane or flying in restricted airspace, the official said. Those scenarios did not apply in this case, according to the official, who said it did not appear the plane was doing anything wrong at the time.

The flight also would have been picked up at Joint Base Elmendorf-Richardson on radar used as part of the North American Aerospace Defense Command's system to monitor all air traffic entering U.S. and Canadian airspace, Air Force Capt. Anastasia Wasem said. Flights originating locally would be considered friendly, she said.

Workers load the remains of a small plane that crashed into two office building in downtown Anchorage, Alaska, onto a flatbed trailer on Tuesday, Dec. 29, 2015. (Bob Hallinen/Alaska Dispatch News via AP) KTUU-TV OUT; KTVA-TV OUT; THE MAT-SU VALLEY FRONTIERSMAN OUT

Workers load the remains of a small plane that crashed into two office building in downtown Anchorage, Alaska, Tuesday, Dec. 29, 2015. The pilot was not authorized to fly the aircraft used in volunteer search-and-rescue missions, authorities said. (Bob Hallinen/Alaska Dispatch News via AP) KTUU-TV OUT; KTVA-TV OUT; THE MAT-SU VALLEY FRONTIERSMAN OUT

Workers load the remains of a small plane that crashed into two office building in downtown Anchorage, Alaska, Tuesday, Dec 29, 2015. The pilot was not authorized to fly the aircraft used in volunteer search-and-rescue missions, authorities said. (Bob Hallinen/Alaska Dispatch News via AP) KTUU-TV OUT; KTVA-TV OUT; THE MAT-SU VALLEY FRONTIERSMAN OUT