As news of the deadly mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, unfolded last week, Pia Guerra, a 46-year-old Vancouver-based artist, felt helpless.
She couldn't bring herself to go to sleep, so she began to draw.
About 6am she came up with an idea. One of the first victims identified among the 17 people killed was Aaron Feis, an assistant football coach and security guard. Feis was shot after reportedly throwing himself in front of students during the rampage. Guerra was moved by the thought of this heroic man, the father of a young child, standing in front of bullets for students.
"It's not often that an image pops in your brain and you feel a lump in your throat," Guerra told The Washington Post.
"I need to get this down before time dilutes it," she recalled thinking as she began to sketch the image.
Around midday, Guerra posted her editorial cartoon on Twitter. She called it "Hero's Welcome."
The cartoon portrays a young freckle-faced girl reaching out to hold Feis's hand. "Come on Mister Feis!" the girl is saying. "So many of us want to meet you!"
Behind the girl stands a massive crowd of young children and a few adults, looking to Feis with wide eyes. They look solemn and innocent. Two of the children are waving. The crowd, Guerra says, represents the children and adults who have been killed in mass school shootings.
More than 200 people have been killed in mass school shootings in the United States since the mid-1960s, according to a Washington Post tally. On Feb. 14 in Florida, authorities say, a gunman entered the high school and fired his AR-15 assault-style rifle, killing 14 students and three staff members. Nikolas Cruz, 19, a former student at the school, has been charged with 17 counts of premeditated murder.
Most of the children and teachers in Guerra's cartoon, including the girl reaching out to Feis, represent victims killed in the Sandy Hook Elementary School shooting in Newtown, Connecticut, in 2012, which left 28 dead.
Guerra's cartoon evoked striking responses across social media. By Tuesday morning, the image had been retweeted more than 18,290 times, and Guerra's Twitter account had been overwhelmed with emotional messages.
"I saw this earlier, and I sat in front of my students and cried," one teacher tweeted on Friday. "And then I showed it to them, and they cried, too. Very powerful. The most beautiful thing I've ever seen."
"When I saw your drawing, I cried hysterically for a half-hour and I couldn't stop," another person posted on Twitter. Guerra even said she heard from a parent of a girl who died in the Sandy Hook massacre.
Guerra had offered the cartoon to the daily comics publication the Nib, for which she is a regular contributor. But the Nib ended up choosing a different cartoon of Guerra's for publication, so she chose to share "Hero's Welcome" on social media.
To many, Guerra said, the cartoon depicted the children and teachers welcoming Feis to heaven. Guerra knew before she posted the image that many may interpret it in a religious way, and "that's fine," she said. But that was not her intention.
Guerra describes herself as an atheist. After a tragedy, she said, she grows tired of always hearing about angels and heaven and the idea that the dead all end up in a better place.
"Wherever all these wonderful people are, they're not here," she said. But the message, she said, "is beyond that."
She wanted to show the immense collective magnitude of the loss, a visual tally of just how many people have been killed in mass school shootings. She also wanted to evoke the nature of the youngest victims of these massacres - the wide-eyed, gentle essence of a child.
"This is who they are," she said in a phone interview, her voice catching. "This is all that we lost."
The simplicity of the cartoon, she said, means it may carry different meanings for different people. "When you leave something open enough to interpretation, more people can find something in it," she said.
In addition to significant praise, Guerra's cartoon also drew a wave of criticism for seemingly portraying only white children and adults, despite the fact that many people of color have died in these shootings.
"That was a direct result of rushing and not paying more attention to the makeup of the crowd, and maybe making a point about how these things always seem to happen in white suburbia and totally mucking it up," Guerra said. She lamented the lack of representation in the image.
"I'm taking the note and I promise to do better," said Guerra, whose father is Chilean and mother is Finnish. She was born in New Jersey and moved to Canada when she was 6 years old.
Guerra co-created the science fiction comic book series "Y: The Last Man" alongside Brian K. Vaughan. It began publication in 2002. But since the 2016 election, her cartoons have focused predominately on President Donald Trump. It's her way of "venting," she said. One of her most widely shared cartoons, from January 2016, depicted Trump as a child sitting on the lap of Steve Bannon, then the White House chief strategist.
She is accustomed to provoking a range of reactions with her cartoons - usually anger, frustration or humor. But "Hero's Welcome," she said, was entirely different.
"It's more emotional, it's more personal . . . a gut reaction," she said. "This is a whole other level."
Guerra plans to continue to create images related to last week's shooting.
"We should be engaged in this," she said. "We should use our voices . . . whatever it is we have to amplify what's important to us."