After two years of cancellations due to COVID-19, Haitian Unity Parade organizer the Rev. Dieufort Fleurissaint said he fielded concerns this year about a different kind of public safety threat: a violent racist attack.

“People called and asked if we should do this, with what’s happening,” Fleurissaint said. “You never know where or when these things can happen, these attacks against Black immigrants.”

The day before thousands marched down Blue Hill Avenue in Mattapan, where roughly one third of residents are of Haitian descent, a man opened fire at a grocery store in a predominantly Black neighborhood of Buffalo, New York, killing 10 and wounding three others. The shooter left behind a document centered on the idea of a plot to replace the white population with immigrants, a white supremacist conspiracy theory that inspired the 2019 Christchurch mosque shootings in New Zealand, where the shooter warned of “White genocide.”

From Blue Hill Avenue to Harambe Park, churches, organizations, businesses, schools and dance troupes were highlighted at Sunday’s event celebrating Flag Day, which commemorates a meeting of Haitian revolutionaries in 1803 that would become a unified force against French colonizers, a holiday historically rooted in resistance.

“If our forefathers could have fought for 13 years to overthrow a superpower, what can't we do? So I won't let any act of white supremacy try to steal my joy,” Louijeune said. “Do I wake up with a heavy heart? Absolutely. But I mean, that's the narrative that Black folks have known in this country for so long, that dance of joy and sorrow.”

“White supremacy and gun violence are grave threats to all of our communities and the brutal, hateful, and targeted shooting in Buffalo is devastating,” U.S. Rep. Ayanna Pressley, whose district includes Mattapan, tweeted Saturday. “Praying for everyone impacted. It is so far beyond time for Congress to act and save lives.”

At the parade in Mattapan on Sunday, Boston City Councilor Ruthzee Louijeune invoked Pressley’s words from election night in 2020. “[She] always says joy is an act of resistance,” Louijeune said, “so there's no way I was not going to be here to celebrate with my people.”

The annual celebration of Haitian culture is an example of the resilience of Black immigrant communities, Louijeune said.

“Oppressed folks have to learn resiliency by force, but we're still here and we're still standing after everything that has been thrown our way,” she said. “We have to cling to these moments of joy, because if not, then we'll have nothing.”

Haitian Flag Day celebrations are planned in Brockton, Medford and other communities throughout Massachusetts in honor of Haitian-American Heritage Month.