The morning of March 16, 2009, brought sunny skies and rising temperatures to the Mont Tremblant ski resort in Québec, Canada, the cusp-of-spring day beckoning visitors outdoors to its cobblestone-lined streets and scenic mountain trails.

The resort's guests that Monday included 45-year-old actress Natasha Richardson, who was ready to throw herself into ski lessons with the same aplomb that had produced celebrated screen roles in Patty Hearst and The Parent Trap, as well as a Tony Award-winning performance in Cabaret.

But what started out as an idyllic day ended in disaster for Richardson and her family, including actor husband Liam Neeson and their two sons, Micheál and Daniel, as a seeming commonplace fall by an inexperienced skier turned fatal through the questionable decisions that loomed painfully large in hindsight.

Richardson initially declined medical assistance

At around noon, Richardson was on the hill with an instructor and nearing the bottom of a beginners' trail when she toppled over; her head, free from the confinement and protection of a helmet, banged against the still hard-packed snow.

Richardson shrugged off the spill, but her wary instructor sought a second opinion from the ski patrol, who subsequently called for an ambulance.

However, Richardson insisted that she was fine. She signed a waiver to decline medical help and walked to her room at the Hotel Quintessence, her instructor and a member of the ski patrol tagging along just to be sure.

Meanwhile, paramedics arrived in an ambulance at 1 p.m.. Learning that their services weren't needed, they disappeared back the way they came a few minutes later.

Natasha Richardson

Natasha Richardson in 2005

More time was lost as she was taken to two hospitals

Back in her room, Richardson initially showed no ill effects from the incident. She even made light of it in a phone call to her husband, in Toronto to shoot a film, relaying the news with a casual, "Oh, darling. I've taken a tumble in the snow."

But anxiety levels climbed as the actress began complaining of a headache and showing signs of confusion. Another call for an ambulance was placed at 3 p.m., the dispatcher indicating the increased urgency of the situation.

Sent to a nearby hospital in Sainte-Agathe, Richardson displayed promising vital signs and breathed easily with help from oxygen. However, her orientation continued to plummet, and the hospital's staff realized they weren't equipped to handle what had become a dire situation. She was loaded into another ambulance just before 6 p.m., this time bound for a Montréal trauma center some 55 miles away.

Her husband found her brain-dead upon arriving at her side

By that point, Neeson had already received word that his wife was in serious trouble and quickly left the Toronto production. As the actor described to Esquire in 2011, he arrived at this forbidding "Dickensian" hospital, only to find that no one recognized him, or had any intention of letting him past the emergency room.

Wandering outside, Neeson came upon a sympathetic nurse who directed him through a back door. He finally found Richardson, hooked up to life support, and received the grim news that she was brain-dead.

Staring at the X-ray which revealed her brain being "squashed up against the side of the skull," Neeson recalled the pact he'd once made with his wife, both promising to "pull the plug" if the other wound up in the exact predicament that was staring him in the face.

"And I went into her and told her I loved her," Neeson later told Anderson Cooper on 60 Minutes. "Said, 'Sweetie, you're not coming back from this. You've banged your head. It's – I don't know if you can hear me, but that's – this is what's gone down. And we're bringing ya back to New York. All your family and friends will come.' And that was more or less it."

Richardson was flown to New York, the site of her many Broadway successes and the home she shared with Neeson, and admitted to Lenox Hill Hospital on Manhattan's Upper East Side. There, surrounded by loved ones, she was removed from life support on March 18, two days after what was supposed to be a fun adventure on the slopes.

The autopsy confirmed that Richardson's head bump had resulted in an epidural hematoma, a condition in which blood pools between the brain and skull. It also sparked the unavoidable and unanswerable questions about whether the tragedy could have been avoided, either by the direct airlifting of Richardson to the Montréal hospital to save precious time or by the simple act of her wearing a helmet.

Natasha Richardson funeral

Pallbearers carry Natasha Richardson's coffin to her gravesite on March 22, 2009

Neeson and their children drew inspiration from her memory

Richardson's absence still felt unreal to Neeson by early 2014, when he confessed to Cooper that he sometimes expected his wife to walk through the door. Still, he had healed enough to gain some perspective, noting that she was "keeping three people alive" through the donation of her organs.

Their children also managed to move on from the devastating loss, in part by finding inspiration from their mother's words and actions. David, just 12 at the time she passed, went on to found the environmentally friendly clothing line Pine Outfitters.

"She was always about, 'Don't ever feel like you have to be forced down a tunnel to fit in,' he told the New York Post in 2019. "'Do what you want to do, but do it to your best and be generous with it.'"

And Micheál, one year older than his brother, eventually took on his mother's last name and entered the family business. His first leading film role came opposite Neeson in the 2020 comedy-drama Made in Italy, about a father and son who cope with the loss of the wife and mother who bound them together.

The production provided an opportunity to reflect on things with his old man, of course, as well as the other cast and crew members who were navigating the challenging experience of losing a loved one. "That's where I felt Mom, in a way," Micheál explained to Vanity Fair in 2020. "Through everybody."