A deadly cargo plane crash on the North Shore two years ago was likely caused by one pilot's intoxication, according to investigative findings released Thursday.

The Swearingen SA 226 aircraft plummeted into a heavily wooded area near Crown Mountain just six minutes after taking off from Vancouver International Airport in April 2015. 

The captain and first officer, who were the only people onboard, both suffered fatal injuries.

Though the plane departed around 7 a.m., the Transportation Safety Board said toxicology testing determined the captain had consumed a "significant amount of alcohol" that day.

"As a result, alcohol intoxication almost certainly played a role in the events leading up to the accident," the TSB said in a news release.

Investigators determined the Swearingen took a steep dive that caused it to exceed the plane's structural limits and break up mid-flight. Rescue crews found the two pilots along with the wreckage hours later.

In response to the tragedy, the TSB is recommending a substance abuse program that would include educational initiatives, rehabilitation services, and mandatory testing.

"In Canada, regulations and company rules prohibit flying while impaired, but they rely heavily on self-policing," board chair Kathy Fox said in a release.

"We realize that employees within Canada's aviation industry will have concerns under any possible testing regime… This is why we recommend that the substance abuse program consider and balance the need to incorporate human rights principles enshrined in the Canadian Human Rights Act with the responsibility to protect public safety."

Though investigators believe the pilot's state played a role in the crash, they identified two other possible scenarios. One is that the heaters that provide airspeed information were off or malfunctioning. The other "involves a number of flight-specific factors that are consistent with an intentional act," the TSB said.

The full report into the crash is available of the Transportation Safety Board website.