It has been 25 years since the Rwandan Genocide, during which period the Hutu majority killed 800,000 minority Tutsis and moderate Hutus.

Despite the scale, the United States did not intervene at the time — a decision then-President Bill Clinton has since said he regrets.

Joining Boston Public Radio to look back on the tragedy was Charles Sennott, founder of The GroundTruth Project and a WGBH News analyst.

"It's really hard to understand the depth of horror that happened 25 years ago in Rwanda," Sennott said.

Read more: Rwanda's Genocide Victims Remembered 25 Years Later

Sennott said that, today, memorials are taking place across the country to mourn the 100-day period when so many Rwandans were killed.

"[April] 7 began a 100th day period of mourning and reflection inside Rwanda, a country which — to give listeners some hope — has had an amazing transformation as a country," Sennott said.

"There's been a tremendous spirit of resilience and of trying to reconcile its past," he continued.