Searchers used personal watercraft, a helicopter, a kayak, a motor boat and a privately-owned drone Thursday to search the fast-moving San Jacinto River in Montgomery County.
An 18-year-old boy disappeared after swimming with his 19-year-old girlfriend Wednesday night.
"You could tell the point she went from swim to me to OMG, where did you go? Complete panic," said Terrence Morrison.
He was fishing about 6:30 p.m. when he heard the cries for help.
He told Local 2, "Within seconds, the boy was laboring for air, for swimming, for everything. Immediately I grabbed a pole and the phone and ran down the bank and called 911. Followed them as far as I could."
The mother of Jared Brimhall confirmed her son was missing. She told Local 2 that he is the father of a 2-month-old baby and is to graduate from Conroe High School this weekend. Brimhall said her husband spent all night on the river searching for their son.
Brimhall's friend, Cody Day, said, "Me and him would always go swimming in this place. But this is the first time he's gone out too far and actually gotten carried away."
Searchers say the river is full of debris which makes it tough to thoroughly search.
Lt. Brady Fitzgerald with the Montgomery County Sheriff's Office said, "We haven't had a rain in a long while so we have additional items in the river. We have anything from trees to rebar to concrete to garbage inside the river. That stuff is floating on the top and bottom. So it's making the search extremely difficult."
Crews have finished their search for the night and will start the search again Friday morning.