12:30 PM PT -- Sources close to Katharine McPhee tell us their son's nanny, who they considered family, passed away. We still don't know what the circumstances are surrounding her death, but we're told Katharine is currently en route to the U.S.
We've reached out to a rep for Katharine, but so far, no word back.
Singer Katharine McPhee just went MIA from her concert tour in Asia ... and it's all because of a family emergency.
Katharine posted a statement on Instagram Friday ... apologizing to her fans for missing the last two shows in Jakarta on the Asian leg of her tour with her musician husband, David Foster.
She explained they "had a horrible tragedy in our family" and she had to return home to be with loved ones.
Katharine also said she hopes to come back one day and perform for the crowd.