It was probably the worst day of his life: On December 18, 1972, US President Joe Biden (80) received the news that his first wife Neilia and his daughter Naomi had been killed in a traffic accident. 50 years after the tragic event, Biden has now remembered his deceased family in an emotional ceremony.

Together with his wife Jill (71) and other family members, he attended a memorial service at St. Joseph's Catholic Church in Delaware, reports the US magazine "People". His son Hunter (52), who was seriously injured in the accident, also took part. The family placed a large wreath of white flowers on the grave.

"When I got the call back then, I knew immediately that something bad had happened," Joe Biden revealed in a speech in 2012. "I just felt it." The US Democrat was about to be sworn in as a senator and was with staff in the Capitol when the news broke.

"I looked up and said, 'God, you can't be good, how can you be good?'" Biden, a devout Catholic, recalled the day.

Neilia Biden, then 30, was on her way home from Christmas shopping when her car collided with a tractor. Both she and her little daughter Naomi (1) died, and her sons Hunter and Beau (then two and three years old) were critically injured.

Tragic: In 2015, Joe Biden lost another of his children: son Hunter died at the age of 46 from a brain tumor.