She talked to a flight attendant, who moved her to another seat.
Delta said it does not tolerate "the harassment or assault of a passenger by another."
“After deplaning, Ms. Luh first informed a Delta agent that she had been improperly touched on the leg by another passenger. Delta then immediately reported the incident to local law enforcement for their handling,” the company said in a written statement.
After the incident the FBI said: “What was reported was allegations of simple assault. There was not enough evidence to detain or charge anyone.”
According to Luh, Delta gave her a $200 voucher for future travel on the airline.
In the suit, Luh is seeking $1 million in compensatory damages and $5 million in punitive damages.
Delta said it is aware of the lawsuit “and we intend to vigorously oppose it.”
In a separate suit, passenger Allison Dvaladze alleged a passenger groped her on a Delta flight from Seattle to Amsterdam in 2016. She alleged Delta failed to change its policy or improve its flight crew training after she pushed for action for two years.
Delta declined comment on that incident due to pending litigation.
The Association of Flight Attendants union earlier this year called for the formation of a task force to identify guidelines for responding to sexual assault and harassment aboard commercial airplanes.