There was a large police presence at 806 Katy Fort Bend Road near I-10. The Harris County Sheriff's Office said a deputy was taking a report on a terroristic threat at a business.
In a later update, officials said a probationary deputy was chasing a suspect when the fall into the bayou happened.
The deputy was taken out of the water and taken to the hospital for precautionary evaluation, HCSO said.
One suspect was taken into custody while deputies searched for a second suspect who reportedly attempted to get away in handcuffs in the tunnel system under the road.
"We got him in the drainage ditch. We lost him in the tunnel system underneath the roadway," deputies told dispatchers. "He is lost underneath the roadway in the drainage ditch."
Deputies later found the second suspect, who is 17 years old.
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