The 31-year-old former University of Houston student spent time with rebel fighters after entering the country from across the Turkish border in May, providing photo coverage of the war for the Post, McClatchy Newspapers and NPR.
But his last message on Twitter was August 11th — two days before a KUHF feature story on his work.
"Movement through the country has been lots of back roads, lots of walking, lots of dramatic situations. You know, like any insurgency, it's a very fluid battlefield. So there's not really a front line anywhere. There's a front line in each little town."
That phone interview was conducted a couple of days before Tice's last Tweet. Now his family and colleagues are concerned for his safety.
He had planned to leave Syria in mid-August, but a journey to the border can take several days because of the fighting. Tice's editors are working with the State Department to retrace his movements.
Austin Tice's last Tweet:
Spent the day at an FSA pool party with music by— Austin Tice (@Austin_Tice) August 11, 2012
@taylorswift13. They even brought me whiskey. Hands down, best birthday ever.