According to other drivers involved, there was an earlier two-car crash, and that's why people on the road were stopping.
The 18-wheeler driver told ABC13 he did not fall asleep. He says he just couldn't stop fast enough when someone cut him off.
WATCH: Dashcam video shows moment 18-wheeler slammed into vehicles
Dashcam video shows 18-wheeler crashing into several other cars
Herman confirmed a Precinct 4 deputy in his personal vehicle was involved in the crash.
Two children and an adult in a white Hyundai Accent were taken to the hospital with minor injuries.
At one point, all lanes were shut down but have since reopened.
9-vehicle wreck involving 18-wheeler blocking I-45 NB at Mt. Houston