HOUSTON (KTRK) -- The Harris County Precinct 8 Constable's Office is looking for a man who was swept away by flood waters overnight in the Clear Lake area.On Wednesday morning at about 12:30am, a sergeant with Constable Phil Sandlin's Office spotted a vehicle in the ditch alongside State Hwy 3 near Clear Lake City Blvd. He and another witness saw that the vehicle was occupied by Nurul Alam Chowdhury. The man crawled out of the vehicle's sunroof and was sitting on top of the car as attempts were made to rescue him.Harris County Precinct 8 Constable Phil Sandlin said, "The vehicle was submerged with the front end down deep into the water. He was up on the back part of the roof."A deputy constable and another driver tried to pull Chowdhury to safety, but the current was too fast."They said that the victim had fear in his eyes when he knew they were losing their grip of him," Sandlin said. "At that time, he jumped into the water."Unfortunately, the car and the man were swept away. The sergeant observed the vehicle, a dark colored sedan with a sunroof, wash through a large culvert under the roadway to the east of Hwy 3.Since that time, deputies have been canvassing the area along the ditch line by foot and by four wheeler but have been unable to locate the vehicle or Chowdhury. In addition, the US Coast Guard has been assisting in the search by air. Due to the swift currents, boats are unable to enter the water at this time. Volunteers with Texas Equusearch spent the day searching the bayou on foot and by ATV.A bumper believed to belong to the car has been recovered downstream, near the Bay Oaks subdivision.Anyone who believes they know a missing person who matches this description is asked to contact the Harris County Precinct 8 Constable's Office at 281-488-4040.