Highland Park students walked out to demand gun control. Minutes later, the high school went on lockdown.

• Highland Park students planned a walkout for gun control that was interrupted by concerns a student brought a gun.
• The walkout was in response to last year's July 4th parade massacre and the Nashville shooting last week.
• The school went into lockdown and police later took five students into custody, authorities said.

Highland Park High School students planned a walkout demanding gun control today, but the demonstrations were quickly interrupted by reports of a possible gun on campus. 

The walkout was planned for 10:14am, the same time that the Highland Park July 4th parade shooting started just nine months before.