Video obtained by CBS News Chicago shows the 19-year-old being transported on a stretcher out of the department store.

Two groups of male teens had argued before the shooting, which sparked masses of festivalgoers and shoppers to run for cover, according to a police report.

The 19-year-old woman was shot in the leg while walking with a group of people near Washington and State, outside Macy’s . This was just hours after thousands of people poured into the area for the Mag Mile Lights Festival and Parade.

On Saturday, police said a 19-year-old woman was walking on the sidewalk near the intersection of State and Washington streets shortly before 9 p.m. Police told Ald. William Conway (34th) that a juvenile suspect was in custody Sunday evening in connection with the incident,

The attack sparked masses of festivalgoers and shoppers to run for cover Saturday night when a woman stumbled into Macy's with a gunshot wound, Chicago police said.

A woman was wounded in a shooting Saturday night in the Loop outside the Macy's department store on State Street, as large crowds were packing downtown for holiday festivities.