My mom climbed on Everest. After the Titan submarine deaths, I think of the families who are left behind.

I, like many, have been glued to live coverage of the Titan implosion, ever since the submarine vessel, with five people aboard — who had paid a hefty $250,000 each for the chance to glimpse the Titanic shipwreck from a single 20-inch diameter window — lost contact with its surface ship an hour and 45 minutes into its dive on Sunday.

As the news cycle inched toward what was very likely a burial at sea, I dwelled on the slow-motion movement of the catastrophe. If the submarine was intact — stuck or floating at some unfathomable depth — what would these five wealthy men talk about? Would they have regrets?

The vessel, little more than the size of a minivan, had no seats and a smooth, rounded floor. One occupant, Shahzada Dawood, was a Philadelphia University graduate on board with his 19-year-old son, Suleman.

I fell asleep Wednesday night unable to stop picturing them in the darkness of the deep.

Then, at 3 p.m. on Thursday, under the glaring sunshine of a Boston summer afternoon, the U.S. Coast Guard gave a news conference where it announced that the passengers were presumed dead after discovering debris from the submersible some 1,600 feet from the Titanic shipwreck. “The debris is consistent with the catastrophic loss of the pressure chamber,” Coast Guard official Rear Adm. John Mauger said. “Upon this determination, we immediately notified the families.”

I felt myself exhale, long and slow. At least they had died quickly.

The Titanic, a mass grave site, is now host to five more souls.

Why had the fate of these explorers so captured my attention? Death is as common as mud. Our bodies are vulnerable. And these five deaths — as many have pointed out — are a glaring contrast to the hundreds of migrants who died off the coast of Greece last week, seeking a better life on foreign shores.

I’m no stranger to the vagaries of risk. For years, when I was young, my mother was a professional high-altitude mountaineer in the Himalayas. As a single mother, she climbed on Everest and K2 and Gasherbrum II and Kanchenjunga without supplemental oxygen, leading expeditions with support from National Geographic. She was an explorer of the highest places on the planet.

With the perspective of adulthood, I have come around to gratitude for all those risks she took. I know that being at death’s doorstep, tens of thousands of feet above sea level, helped her heal after she was raped and had an abortion — an event she mourned deeply. Watching her take risks gave me a model of adventurous womanhood, and also gave me the confidence to ride my bicycle around the world documenting 1,001 stories of water and climate change, which somehow landed me in this beautiful profession of journalism that I am proud to call home.

But facing the realities of risk — yes, my mom could die in an avalanche when she left me, and yes, she almost did — gave me a skewed sense of fear. My family jokingly called me Mrs. Potts, after the teapot in Disney’s Beauty and the Beast who worries about everything. I didn’t have control over the world outside me, but I could take it upon myself to inhale fear.

One of my earliest memories of panic is of watching Titanica, a 1992 IMAX documentary film about the Titanic shipwreck. As an elementary schooler, I remember feeling vertigo as the cameras descended underwater, into the dark depths illuminated in blues and eerie sepia. When I saw the shipwreck, I had a panic attack. I felt like I was drowning. I couldn’t breathe. I couldn’t stop crying. It took me exiting the theater and entering the sunshine of the day to remember who I was, and where I was, and that I wasn’t drowning.

Learning to breathe deeply was the only thing that got me out of panic.

On Thursday, after the Coast Guard news conference, I stepped outside into the bright warmth to throw a ball for my dog. I couldn’t help but feel gratitude. I felt days of worry slide down my shoulders. Why do we humans need to plumb the depths of the ocean or the highest reaches of space?

Those places are horrendous. They are inhospitable. They lack breathable air and beauty and joy.

And yet, there will always be people who seek more, who must sink to the deepest depths or climb the highest peaks — leaving behind the people who love them desperately, who hold their breath until they come home again.

I’m lucky; my mom always did come home. But for the five passengers of the Titan — Stockton Rush, Hamish Harding, Paul-Henri Nargeolet, and Shahzada and Suleman Dawood — their families have a different fate. And it is often those left behind who suffer the most.