President Obama hugs Vice President Biden during funeral services for Biden's son, Beau Biden, on June 6 at St. Anthony of Padua Church in Wilmington, Del. (Pool photo by Yuri Gripas via AP)

Sometimes the most important thing a journalist can do is bear witness to grief.

I learned this years ago, when I wrote my first obituary for The Washington Post. It can provide comfort to an individual’s most intimate friends and family while simultaneously conveying that same person’s significance to total strangers. It is a moment to say why someone mattered now that they are no longer here.

On Saturday morning I joined a small cadre of reporters all charged with that duty, and something a little more complicated. We had to share, in real time, how a family and the broader community surrounding them were coping with the sudden loss of someone central to their lives. And we were doing that from the vantage point of the president of the United States, whom we would trail for several hours with our laptops, iPhones and recording equipment in tow.

President Obama follows his daughter Sasha as they walk off Air Force One after arriving in New Castle, Del., on June 6. The first family traveled to Wilmington, Del., to attend the funeral service of former Delaware attorney general Beau Biden, the vice president's eldest son. Biden died of brain cancer at the age 46. (Pablo Martinez Monsivais/AP)

Pool reports are a way to capture what the president is doing when not every reporter can witness it firsthand. Journalists from every medium — print, wires, television, radio and photo — accompany him whenever he leaves the White House and describe what he's doing so others can incorporate it into their own coverage. Nothing in a pool report is proprietary: journalists can use it as if they witnessed it firsthand, without attribution. You cannot store away a particularly nice detail for yourself while pooling; instead, you put it all in a series of e-mails that are distributed to thousands of people while you are with the president.

[Here's why Joe Biden chose President Obama to deliver his son's eulogy.]

Sometimes White House reporters try to pawn off pool duty on their colleagues: it can be a bear, especially if you are also trying to file a story on the event that you’re pooling. Not this time. Every single member of the print pool volunteered to go. Some of them, including Bloomberg’s Margaret Talev and AP’s Josh Lederman, have covered the vice president for years and know him well.

Some aspects of the morning were routine: The ride to Joint Base Andrews, the military bus transport to the terminal and the security sweep take place each and every time we take off on Air Force One. But it was clear this was not an ordinary assignment: All the reporters — just like the members of the first family — were dressed in black.

The motorcade in Delaware from New Castle Air National Guard Base to Wilmington hammered home how different this journey was from others I’ve taken with the president. Motorcade routes are almost always lined at points by onlookers snapping photos with their smartphones; sometimes they hold signs praising — or blasting — President Obama for his policies. This time, as we entered town, not a single sign mentioned the leader of the United States.

"God bless the Biden family," read several. "God bless Beau and Joe," said others. A local pizza joint had changed the lettering on a driveway billboard to say, "Our prayers are with the Biden family."

In this age of hyper-partisanship, it was almost a relief to feel like politics was irrelevant for once.

A woman holds a "God Loves Beau" sign as the hearse and Biden family arrive at St. Anthony of Padua Church for the funeral of Beau Biden on June 6 in Wilmington. ( Mark Makela/Getty Images)

Once we had exited the motorcade’s vans, we were ushered into the back row of St. Anthony of Padua Church. Just a few inches separated us from people in the midst of mourning, who had known Beau Biden much better than we did. We quietly accepted programs, unpacked our gear, set our devices to silent and powered up our computers.

As a pooler, your job is to capture not just the president’s movements but the details others cannot see from a webcast or transcript of the event. Politico’s Edward-Isaac Dovere was serving as the vice president’s print pooler that day, and he relayed several tiny, heartbreaking details in an 11:11 a.m. e-mail to other reporters via Biden’s office:

Just before the door to the hearse opened, the vice president briefly looked up to the sky, and then forward again, his face unmoving. He put his arm around Hallie Biden and then kissed her on the head as they saw the casket, then bowed his head. He reached around his daughter-in-law and rubbed his grandson’s head gently. Biden’s own son Hunter, standing right behind them, reached forward and wrapped his arm around his nephew.

I did my best to provide an account of those details, too — the vice president leaning down to kiss his grandson Hunter’s head multiple times at one point, the draping of the American flag over the casket. As I was typing some of this running commentary into my iPhone, or whispered a question to one of my seatmates to make sure I was describing something accurately, I wondered what the people surrounding us thought. Did they think we were gossiping, in the midst of such a somber service? Did they consider us intruders, or did they see us as people providing a valuable lens into the day’s events? It was impossible to tell.

Vice President Biden places his hand on his heart as the casket of his son is carried into the church before a funeral Mass for Beau Biden at St. Anthony of Padua Church in Wilmington on June 6. (Bryan Woolston/Reuters)

But even as I and other reporters typed away, there were moments when there was no way to keep the sheer impact of the Bidens’ public expression of pain at a distance. The raw emotion of Hunter Biden’s recollection of his brother holding his hand in the hospital after a car crash when they were toddlers, saying “I love you” over and over again, Ashley Biden’s description of the sleepovers she spent as an 8-year-old in her brother’s college apartment; it was impossible to stay aloof. Every single journalist in that back pew cried at some point.

And when it was over, there was one thing that the reporters who happened to be parents wanted to do — get home to our children. As I ran up the stairs of my house to the second floor where my kids were playing, they greeted me with a single — and simple — request. They wanted to make ants on a log, that childhood snack that involves spreading peanut butter on a celery stick and placing raisins on top to simulate the tiny insects at a crawl.

I knew I had to make some tweaks to the stories I had written over the course of the day, but that would have to wait, as I fired off an e-mail to my two editors. “I just got home and I'm headed out with the kids to the store so we can get celery for ‘ants on a log,’" I wrote.

And with that I ushered my children out the door, strapped on their helmets and loaded them on their bicycles. As they pedaled down the alley I thought of Beau Biden riding the escalators with his son at the Democratic National Convention, and how in a day full of weighty moments, this one mattered most of all.