John Krasinski announced the arrival of his and Emily Blunt's first child via Twitter Sunday morning.

"Wanted to let the news out directly," he tweeted. "Emily and I are so incredibly happy to welcome our daughter Hazel into the world today! Happy bday!"

Blunt, 30, and Krasinski, 34, began dating in 2008 and have been married since July 2010.

"The Devil Wears Prada" actress announced her pregnancy back in September and was celebrated at a baby shower at her Los Angeles home in December, according to People Magazine.