Ted Cruz Apologizes for Joe Biden Joke After Son's Death

Beau Biden died Saturday after battling brain cancer.

— -- Republican presidential candidate Sen. Ted Cruz has apologized after making a joke about Vice President Joe Biden while he is mourning his son.

"Joe Biden," Cruz reportedly said to some laughter while speaking at an event in Michigan. "You know the nice thing? You don't need a punchline."

"Vice President Joe Biden," @TedCruz says to faint laughter. "You know the nice thing? You don't need a punch line." #JoeBiden

The vice president's son Beau Biden died Saturday after battling brain cancer. He was 46.

Cruz then took to his Facebook page to apologize.

"It was a mistake to use an old joke about Joe Biden during his time of grief, and I sincerely apologize," he said, according to the post. "The loss of his son is heartbreaking and tragic, and our prayers are very much with the Vice President and his family."