Band 'The Chainsmokers' crash an Illinois high school's prom

ROSEMONT, Ill. (WPVI) -- A surprise guest helped make the Huntley High School prom a night those students will never forget.

The group "The Chainsmokers crashed the high school dance at the Hyatt Regency in Rosemont, Illinois Saturday night.

The Daily Herald reports that the surprise had been weeks in the making. "The Chainsmokers" performed their hit song "Closer" and then ran over to the Allstate Arena for their concert.