Marie Rivard, a trainer for Airline Ambassadors, listened during a training Jan. 23, 2018, for flight attendants, concessionaire staff and airport volunteers at Minneapolis-St. Paul International Airport. (Star Tribune/The Minnesota Star Tribune)

Two weeks before Super Bowl LII, I was flying from New Orleans to Minneapolis when an unusual trio sat nearby. Two young women occupied the window and aisle seats. Between them sat a significantly older man, and the women seemed to defer to and dote on him. It unnerved me.

I thought the women might be victims of sex trafficking, brought to town ahead of the big event, and I didn't know what to do about it.

Now I do: Talk to a flight attendant. Many are trained to spot signs of human trafficking — moving victims for the purpose of forced labor or sex exploitation — and know what to do when they see them, which is to alert authorities on the ground.

The flying public can also step in by texting "help" to 233733 or calling 1-888-373-7888, the National Human Trafficking Hotline. The 24/7 line is run by Polaris, a nonprofit group that fights human trafficking and is supported by the Department of Health and Human Services. Polaris reports that 71 percent of trafficking victims travel on planes.

Delta has trained 56,000 employees to recognize signs of trafficking. A video that aired on planes in January (Human Trafficking Awareness Month) and March 14 (#MyFreedomDay) shines a spotlight on human trafficking and modern slavery — and asks for the public's help. Delta has also placed educational posters at airports, including MSP.

Delta has been amping up employee training since at least 2011, but it is not alone. In 2016, Congress mandated that all U.S. airlines train cabin crews. And the International Air Transport Association, the trade group made up of the world's largest airlines, has asked member airlines to train employees to see and respond to victims and has created training materials.

With employees and 200 million customers, there is a great opportunity "to drive change and ultimately save lives," Allison Ausband, a Delta senior vice president, noted in a news release.

Human trafficking occurs year-round, not just when events bring partyers and money to town. But during Super Bowl LII, nearly 100 people were arrested for trying to buy sex. Keep an eye out ahead of the upcoming NCAA Final Four — and all year round.

Send your questions or tips to Travel Editor Kerri Westenberg at travel@startribune.com, and follow her on Twitter: @kerriwestenberg.