District 2 County Commissioner Brian Maughan reported 5 feet of water in tunnels under the downtown county courthouse and other water damage to the building.
There was also significant flooding and wind-related damage reported at Oklahoma City Community College, 7777 S May Ave., and in the Capitol Hill area south of Oklahoma City, he said.
A police officer at Oklahoma City University said part of the roof on building there fell in, but said nobody was injured. He had no further details.
Wet floors also were reported at the Devon Tower, Metro Transit facility and Oklahoma City Municipal Courts.
Five Metro Transit buses were stranded, but no passengers were aboard, reported Kristy Yager, city spokeswoman.
Flooded streets were reported throughout Oklahoma City as city crew rushed to put up barricades in problem spots to numerous to mention.
“We are overwhelmed right now with calls of people trapped in vehicles in high water, to the point that we are having grave difficulty even responding to all of them,” said Lt. Jay Barnett of the Oklahoma City Police Department. “The flooding is the major problem in the Oklahoma City metro. A lot of that has to do with people who, for whatever reason, instead of sheltering decided to outrun the storm and got caught in it.”
Driving rain and hail were hindering rescue efforts.
“Areas of the city that don't normally flood — we're seeing flooding,” he said. “We're also still dealing with traffic jams that resulted from high traffic volume that appears to have been generated by the storm.”
Dangerous situations developed along interstates heading in and out of Oklahoma City on Friday evening after television weathermen announced a massive tornado had touched down near El Reno, and at least one weatherman warned residents they needed to get underground.
Residents who don't have underground shelters typically head for bathtubs and interior rooms during tornado warnings in Oklahoma. Warned that they needed to get below ground — many apparently turned to the interstates and tried to outrun the storm, leading to gridlock along Interstate 35 and some other highways.
Several thousand people, including an estimated 1,200 passengers, took shelter in a tunnel at Will Rogers World Airport, said airport spokeswoman Karen Carney.
There was “lots of debris on the airfield,” she said.
She estimated people were in the shelter one-and-a-half to two hours before receiving the all-clear signal around 7:30 or 7:45 p.m.
At 9:30 p.m., power was still out at the airport, although some auxiliary power was lighting the terminal.
Southwest Airlines had canceled its flights, and the one Frontier flight scheduled to depart was canceled, she said.
“We still have a terminal full of people,” Carney said. Flooding on Meridian Avenue limited access to the airport.
There was a report of one hangar with a damaged door, Carney said. There was some water dripping from the ceiling and floors were wet from water blowing in the doors, she said.
Downed power lines blocked State Highway 66 near I-40 between El Reno and Yukon.
David Andra, meteorologist in charge of the National Weather Service's Norman Forecast Office, said the bulk of damage was inflicted by a large tornado that developed in Canadian County and weakened as it came into Oklahoma County.
Some smaller tornadoes inflicted lesser damage, he said.
The main tornado touched down in a rural area southwest of El Reno around 5:55 p.m. and initially traveled southeast and east before turning northeast and crossing I-40 to the west of Yukon.
“There was lots of wind -- lots of 80 to 90 mph wind gusts in the area,” said Rick Smith, a warning coordination meteorologist with the National Weather Service.
Smith blamed the flooding on a “huge complex of severe thunderstorms” that moved extremely slowly through Canadian and Oklahoma counties, drifting southeast through Norman, Moore and toward Shawnee.
Oklahoma City Councilman Larry McAtee said his family rode out the storm at Integris Baptist Medical Center. They returned to find extensive street flooding and the power out in their neighborhood at NW 30 and Meridian, he said.
At the Women's College World Series at ASA Hall of Fame Stadium in Oklahoma City, winner's bracket games between Oklahoma and Texas, and Tennessee and Washington were postponed until Saturday.
Flooding downtown poured water into the Cox Convention Center, forcing the postponement of the Oklahoma City Barons' AHL playoff game against the Grand Rapids Griffins.
Brooke Cayot, spokeswoman for Integris Canadian Valley Hospital in Yukon, said 26 patients were admitted there, including one in critical condition. Two pediatric patients were transferred to the Children's Hospital at OU Medical Center. One was in serious condition. Injuries included head trauma, blunt force trauma, cuts and fractures, she said.
Thirty patients were admitted to Integris Southwest Hospital with trauma related injuries. One was in serious condition, Cayot said.
Ten patients were admitted to Integris Baptist Medical Center with storm injuries, including an infant in critical condition.
Six children and two adults were treated at OU Medical Center. One adult was in intensive care, said Eric Ferguson, OU Medical Center spokesman.
And 13 patients were admitted to Mercy Hospital in El Reno, including two in critical condition.
Contributing: Staff writers Bryan Painter, William Crum, Hannah Covington, Nolan Clay, Andrew Knittle, Julianna Keeping, Jaclyn Cosgrove, Tiffany Gibson, Jim Beckel, Robby Trammell, Adam Kemp, Michael McNutt, Carmen Forman and Steve Lackmeyer.