Two days after two floatplanes carrying cruise passengers collided mid-air in Alaska, the cause of the crash is still unclear.

Officials have still not said what happened, but the U.S. National Transportation Safety Board and Federal Aviation Administration are both investigating.

The wreckage of one of the planes, a de Havilland Otter DHC-3 operated by Taquan Air, was pulled from the water at the crash site Wednesday morning.

According to the NTSB's Jennifer Homendy, early indications are that the Taquan plane was heading southwest at some 230 km/h, descending towards Ketchikan from about 4,000 feet at the time of the fatal collision.

"We did not see anything abnormal about this," she said.

Divers were in the water to secure the wreck, which was submerged in more than 20 metres of water when it was recovered.

The second aircraft, a de Havilland Beaver operated by Mountain Air appears to have been heading west-southwest towards Ketchikan and maintaining an altitude of about 3,300 feet, Homendy said.

The debris field of the Beaver is much larger, she added, measuring some 300 metres by 900 metres.

Homendy said once the remains of both planes have been recovered, investigators will try to piece them back together in an effort to see how the aircraft made contact.

The NTSB is also considering conducting visibility testing to find out to what extent the pilots would have been able to see each other.

A preliminary report into the crash is expected in about two weeks, Homendy said. The NTSB will hold any more press conferences before then, but investigators will remain on scene.

The crash occurred in an area just outside Ketchikan, a popular port city for cruise ships. The planes collided in George Inlet Monday afternoon.

Home to jagged mountains and pristine waters, the inlet is a common spot for cruise passengers to take tours, but the increasing air traffic is concerning to experts who spoke to CTV News Vancouver on Tuesday.

The winding fjords can block radio transmissions, so pilots may not be aware of how far away they are from an approaching aircraft.

Crews returned to the inlet on Wednesday to examine the wreckage of the crash. A substantial debris field was left behind when the planes collided, killing six people.

Among the victims are a B.C. couple and an Alaskan pilot who'd been based in Ketchikan.

Ten others were hospitalized as a result of the crash. Four were airlifted to Seattle, while the other six stayed in Alaska. Of those six, three remained in hospital Tuesday evening in "fair condition," and the other three were discharged.

That afternoon, dozens in the community gathered on the street outside the hospital in a show of solidarity.

"It's a tragedy for everybody involved - the community, the visitors - and you can't take it back," a person attending the gathering told CTV News Vancouver.

Members of the public said about 20 boats of Good Samaritans headed out Tuesday to aid in whatever way they could as crews searched for two missing people.

Their bodies were recovered that day, bringing the death toll to six.

In a statement, one of the airlines involved in the crash thanked those who'd responded at the time of the crash, and in the days that followed.

"We are grateful for the dedication demonstrated by the exhaustive search and rescue efforts by these responders and community volunteers resulting in a full recovery," Taquan Air said.

"We are fully committed to understanding this incident and the circumstances that led up to it."

The airline expressed its sympathies to the victims of the crash, which also involved a plane from Mountain Air, and said it will work with investigators to determine how it can improve flight safety in the future.

With a report from CTV News Vancouver's Allison Hurst in Alaska