A motorist has pled guilty to manslaughter for killing a cyclist on Gerritsen Avenue in Brooklyn.

Sean Ryan, 17, was riding on Gerritsen near Florence Avenue on the night of July 17, 2016, when Thomas Groarke, driving the opposite direction in a Honda sedan, crossed the center median and hit him head-on, according to the office of District Attorney Eric Gonzalez.

Groarke, who had four passengers in the car after a day of drinking at a Staten Island bar, was attempting to pass another vehicle at 80 miles per hour when the collision occurred, the DA’s office said. Ryan died instantly.

Groarke had a blood alcohol level of .14 two hours after the crash. He was charged by the late district attorney Ken Thompson with manslaughter, homicide, DWI, and other charges.

Last March, Groarke, 26, entered a guilty plea to second-degree manslaughter, “which was offered by the Court over the prosecutor’s objection,” Gonzalez’s office said. This week he was sentenced to three to nine years in prison.

“This defendant’s reckless and criminal driving took the life of a promising teenager who was doing nothing more than riding his bike,” Gonzalez said in a statement. “I am determined to continue prosecuting dangerous motorists who kill others on Brooklyn’s roadways, which should be safe for everyone who uses them.”

At the time of the crash, Gerritsen Avenue was a speedway with a history of deadly crashes. After Ryan was killed, DOT installed a protected bike lane, pedestrian islands, floating bus stops, and other measures to slow motorists down.