12:10 p.m. A dive team has checked the submerged car and did not find anyone inside it or near it, according to fire department radio reports.
City workers are draining part of the Oklahoma River as part of a sewer line construction project, city Utilities Department spokeswoman Debbie Ragan said.
The sewer line is being extended from the north to the south of the river, which requires the new pipe to be put in underneath the river bed, Ragan said. Crews discovered the car when the water level began to recede.
The Oklahoma River is not actually a river, but a series of man-made lakes on the route of the North Canadian River. The lakes are controlled by gates, and the recreational opportunities on the river are a byproduct of its function as a flood control device.
It is not connected to the city's drinking water supply.
11:40 a.m. A dive team is at the Oklahoma River to check a partially submerged car that has been discovered in the water.