The balloon may have struck power lines when it went down around 7:30 a.m. in pastureland near Lockhart, about 30 miles south of Austin, in an area often used for balloon landings, a county judge and public safety source told CNN.
"First I heard a whoosh," Margaret Wylie, who lives near the crash site, told CNN affiliate TWC. "And then a big ball of fire (went) up. I'd say it got as high up as those lower electric lines."
If investigators confirm 16 people died, the crash will be the most fatal hot air balloon accident in United States history.