On that Tuesday, my two-year-old son woke me around 6:00 a.m., and I groggily turned on the TV in our living room to pop in one of his favorite VHS tapes.

He had quite a collection. Bear in the Big Blue House, Baby Mozart, VeggieTales, and loads of Sesame Street. It would still be eight months before he received his official autism diagnosis, but his repetitive interest in these videos was already very apparent.

That morning, I was grateful for his avid interest in those tapes so I could catch a bit more sleep before the true start of our day.

Before I switched the television’s feed to the VCR, the screen filled with an image of smoke billowing from a tall building. It was after 9:00 a.m. on the East coast, and reporters with anxious voices were saying something about an airplane, possibly two. The newscasters were clearly caught off-guard and trying to understand what was happening.

I started my kid’s video on our only TV set, moving quickly to replace the real-time view of New York City with the bright neighborhood of Sesame Street. I went to my room to turn on my bedside radio, telling my husband that something had happened back East. I laid on our bed to listen, more sleep no longer an option.

It was unsettling to hear the radio announcers' fear and confusion as they struggled to keep their voices steady. Within a few minutes, I listened in shock as the newscasters reported the South tower collapse, while the cheery sounds of Elmo’s World came from the other room.

Later, of course, I would see the replays of the planes crashing, the imploding buildings, the rubble and dust and terror, along with footage of the wreckage in Pennsylvania and at the Pentagon – but I got a reprieve from the visual stress of the live coverage thanks to my kid’s videos.

I still didn't grasp the full scale of what was happening, and tried to continue our day as planned.  I got our son ready and took him to his new “toddler preschool” at a nearby Montessori school. He’d just started there at the end of August, his first experience in a structured setting away from mom. We were still in that early phase of adjustment that left us both crying at drop-off (and through a good part of the morning). An experience that with hindsight I know was more than just typical separation anxiety.

On returning home that Tuesday, I found myself standing in front of the TV, watching the news coverage in disbelief. I called my grad school history department – yes, my afternoon class would still be held – and tore myself away from the television long enough to finish and print out my assignment, a paper that was feeling more and more irrelevant.

My son’s school called soon after, cutting the morning session short. They were asking everyone to come pick up their children, they would be closing the school for the day. Everyone was on edge, unsure if our country was under an extended attack, worried for relatives in New York and DC. It was best for all the children to be at home, for now.

My son’s abbreviated daily progress sheet for that day is blank under “Activities.” A scrawled note at the top reported: “Did pretty well. Settled down within 15 min!”

Later that day, I walked across an eerily deserted university campus under a deathly quiet blue sky. That silence – all flights still grounded and most people hunkering inside to watch the news – shook me more than anything else I’d yet heard that day.

In class, our planned discussion of 20th century American history – which stories should be told and how best to bring them to a general audience – had been upended by the morning’s tragedies. We shared what we knew so far, trying to piece together what it all meant. There were still rumors and fears of more planes, more attacks.

I wondered aloud why we were there, sitting in class, and not home with our families.

Then, fueled by my growing unease and guilt, I committed the ultimate sacrilege, voicing doubt that any of this history we were studying mattered at all, when the world outside was on fire.

I remember my professor and classmates looking a little stunned and not knowing how to respond to my heretical language. I’m sure a few of them spoke about the critical place for history, and historians, in helping us understand our past so that we can better shape our future.

Which I, of course, believe as well. I was in this program to learn how to collect, tell, and honor peoples’ stories.

At that moment, I didn’t grasp that this day, and the days and months to follow, would be exactly the type of event that historians would be documenting to pass down to the next generation and the next.

On that Tuesday, I just wanted to be home with my family, watching Sesame Street.

On this 20th anniversary of the 9/11 attacks, the essential work of historians, archivists and curators continues – to preserve, record, and interpret our collective memories of that day and the months and years that followed. You can share yours (and read others) at the Smithsonian’s National Museum of American History.