A Los Angeles man pleaded guilty Thursday to a misdemeanor count after his drone crashed into a police helicopter, prompting an emergency landing, federal prosecutors said.

It's believed to be the first criminal conviction for unsafe operation of an unmanned aircraft in the nation, the U.S. Attorney's Office for the Central District of California said in a statement.

Andrew Rene Hernandez, 22, of Hollywood, pleaded guilty to the single count in a plea agreement, according to court records.

He flew the drone just after midnight on Sept. 18 because he was curious after hearing a police helicopter and sirens, according to court documents.

Read more: NBC News