BARBARA WALTERS was so se­verely injured in a terrifying fall at a pre-inauguration party that doctors were concerned she may have suffered a potentially deadly brain injury.

The 83-year-old broadcaster tumbled down the stairs at the home of British Ambassador Peter West­macott in Washington, D.C., on Jan. 19, knocking her unconscious and leaving her covered in blood from a gaping wound on her forehead. She was rushed by ambulance to a local hospital, where she was held so that doctors could monitor her for life-threatening complications from the injury.

IN AN EXCLUSIVE ENQUIRER INTERVIEW, a par­tygoer who witnessed the frightening fall said Barbara was “lucky she wasn’t killed.”

“She hadn’t been drinking,” the eyewitness was quick to point out. “But it was her fault because she’s stubborn and wouldn’t let anyone escort her down the steps. When someone tried to hold her arm to steady her, she got angry and snatched her arm away. And that’s when she missed a step and fell headfirst down the stairs. She didn’t even put her hands out to stop the fall. It was awful.

“She landed with a sickening thump at the bottom of the stairs. She could have broken her neck or hip. Instead, she hit her forehead and was knocked unconscious. She was covered in blood.

“I thought she was dead!”

Fortunately, she regained consciousness within a few minutes.

Incredibly, when Barbara came to, the plucky news legend “asked for someone to get her car,” said the source. But someone called 911 and she was transported to The George Washington Uni­versity Hospital, where it was determined that she had suffered a concussion.

New Jersey-based surgeon Dr. Steve Fallek ex­plained to The ENQUIRER that the real danger after a patient sustains a jarring blow to the brain, like the one Barbara suffered, is that she could develop a “hematoma,” a pooling of blood in the brain. A hematoma, he noted, could lead to “brain injury and death.” Actress Natasha Richardson, wife of actor Liam Neeson, died after sustaining a hematoma after a skiing accident in 2009.

Because the brain injury risk was so significant, Barbara was kept under observation at the hospi­tal.

Dr. Joseph Maroon, renowned team neurosur­geon for the Pittsburgh Steelers, explained: “Even if they did a CAT scan when she arrived at the ER, you can have delayed effects and onset of blood clots in the brain.”

Keeping her in the hospital, he said, would en­able her physicians to treat her quickly should she start to show symptoms of a hematoma, such as loss of coherency or consciousness.

Barbara’s accident forced her to miss President Obama’s inauguration ceremony, but it could have been much worse. Said the source: “She’s lucky to be alive.”

UPDATE: Whoopi Goldberg said today Babs is also NOW suffering from chicken pox and remains hospitalized.