Flight attendant Shelia Fedrick said she instinctively felt something was off the moment she spotted a girl with greasy blonde hair sitting in the window seat of aisle 10.

She was working a flight from Seattle to San Francisco when her gut instincts told her that something was up. The girl “looked like she had been through pure hell,” Fedrick, 49, told NBC News.  

Fedrick works for Alaska Airlines. She guessed the girl, who was travelling with a notably well-dressed older man, was about 14 or 15 years old. She attempted to engage the pair in conversation, but said the man became defensive.

“I left a note in one of the bathrooms,” Fedrick said. “She wrote back on the note and said ‘I need help.'”

Fedrick said she called the pilot, told him about the passengers and when the plane landed, police were waiting in the terminal.

But while intuition played a critical role in saving this young girl, flight attendant Nancy Rivard’s Airline Ambassadors program was key. Through the program, Rivard trains flight attendants on how to spot the signs of human trafficking.

Since 2009, Airline Ambassadors has been working to make sure flight crew personnel is trained to spot and report a trafficker who is flying with a victim.

Approximately 100 flight attendants volunteered for last week’s session in Houston. Former victims related their experiences to the flight attendants. In-flight crews were taught to look for passengers who appear to be frightened, ashamed or nervous. They were also trained to spot someone who doesn’t appear to be a parent or relative and children or adults who appear bruised or battered.

Crew personnel are also instructed to observe a passenger who is with someone who insist on speaking for the alleged victim, doesn’t let them out of their sight or becomes defensive when questioned as victims can sometimes appear to be under the influence.

U.S. Immigration and Customs Enforcement arrested 2,000 human traffickers and identified 400 victims last year.