A mysterious wave of text messages swept America's phones while many slept, delivering largely unintelligible missives from friends, family and the occasional ex.

  

The best explanation seems to be that old texts sent in the spring suddenly went through. Two people said they figured out the original messages were never received. It's not clear why this months-long delay happened. Phone companies blamed others and offered no further explanations.

  

Mobile carriers offered unhelpful explanations for the weird-text phenomenon, which according to social media appeared to be widespread.

  

A Sprint spokeswoman said it resulted from to a "maintenance update" for messaging platforms at multiple U.S. carriers and would not explain further. T-Mobile called it a "third party vendor issue." Verizon and AT&T did not answer questions.