WASHINGTON (WUSA9) -- A local woman is opening up about a harrowing ordeal aboard a crowded Metro train last week.

Jenny Bruns says she was assaulted after telling a fellow Green Line passenger to wear her headphones.

The suspect in the altercation is a juvenile, so Metro Transit police did not identify her, but police say she has been charged with assault.

Bruns shot chilling cell phone video of the woman who allegedly attacked her, as she attempted to get away.

"She beat me up! She beat me up!" Bruns screams in the video.

The ordeal unfolded last Wednesday afternoon. Bruns was taking Metro to the Navy Yard stop, which is just steps from her home. Loud music on the train annoyed her.

"Me and my big mouth, I called down the train 'Put your headphones on!'" Bruns said.

The music continued to blare.

"So I called a little louder, 'Put your headphones on!'"

She says a young woman charged at her.

"She was angry. She was hostile," Bruns said.

Bruns admits, she cursed her out. But never anticipated what would happen next.

"She grabbed my hair. She must have hit me against the poles because I ended up with goose eggs here," Bruns said.

Both women got off the train at Navy Yard. Bruns raced up the escalator to the Metro station manager kiosk.

"I was like 'Help me, Metro people! Help me! I was just beaten on the Metro!' I had blood running down my face. I could feel it. And they didn’t stop her!" Bruns said.

Moments later, the suspect came out of the elevator.

"I’m like, 'There she is, there she is! Help me! Somebody help me! She beat me up on the Metro!'" Bruns said.

Bruns needed seven stitches above her eye. One week later, other cuts and bruises are still visible.

A few blocks into that chase, bystanders and police eventually did step in to help. The teenager was handcuffed and arrested.

In a statement, Metro said "With the exception of MTPD officers, Metro employees are not law enforcement and cannot perform law enforcement functions. However, we can confirm that MTPD was notified of the altercation aboard the train and did respond."

Because there is no hunt to identify or locate a suspect, D.C. police will not release any surveillance video of the incident.

Metro rules DO require headphones to be used for all audio and video devices.