Doug Lane had to make one of the most difficult decisions of his life last January.

An Army Black Hawk helicopter on a training mission and an American Airlines flight landing at Ronald Reagan Washington National Airport collided over the Potomac River, less than a mile from the runway.

Lane’s wife, Christine, and 16-year-old son, Spencer – an award-winning figure skater – were on board the commercial jet.

More than 400 miles away, Lane was with their younger son at home in Rhode Island.

“There’s no playbook that you ever learn about (this),” he said. “I have my wife and son potentially in the Potomac River. Am I supposed to immediately leave and go down there? Am I supposed to stay with my son? Am I supposed to bring him with me?” he thought as he struggled with the decision.

He ultimately decided to leave his son with family, while he and his sister traveled to face the devastation.

The crash – the deadliest US aviation accident in over 20 years – killed 67 people – 64 passengers and crew members on the jet and three soldiers on the helicopter.

A year’s worth of investigative meetings and hearings on Capitol Hill would follow.

Now a federal investigation has nearly concluded, and the National Transportation Safety Board has determined the close helicopter routes and the Army crew’s perception of the wrong plane to be the probable cause of the collision.

In the days following the collision, Lane and the other victims’ families felt tremendous sorrow and loss after suffering the unimaginable. Mixed within those unbearably difficult moments were the instances of kindness and generosity shown by the first responders and personnel on the scene who, families say, treated them and their loved ones with respect and compassion.