Skip to Content
Streetsblog New York City home
Streetsblog New York City home
Log In
Brooklyn

Eric Gonzalez Convicts Drunk Driver of Manslaughter for Killing Cyclist on Gerritsen Avenue

DOT installed a bikeway and other safety measures after a drunk driver killed Sean Ryan on Gerritsen Avenue. Photo: DOT

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.

Sean Ryan
Sean Ryan
Sean Ryan

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.

Stay in touch

Sign up for our free newsletter

More from Streetsblog New York City

New Details: Hochul’s Car Insurance ‘Affordability’ Pitch Will Shortchange Crash Victims

Hochul's Uber-backed bid to make car insurance affordable hides harmful policies for victims of car drivers.

January 23, 2026

State Pols Could Regulate E-Bikes Despite Not Knowing What They Are

State lawmakers are flirting with the idea of regulating e-bikes as if they were cars, but don't have all the facts.

January 23, 2026

Letter to Mamdani From Maryland: Free Buses Are Working Great

No fares, no homeless encampments, high-quality service. One suburban county shows the way for the new mayor.

January 23, 2026

Friday’s Headlines: Redesign Not Crackdowns Edition

Mike Flynn was great on WNYC. Plus other news.

January 23, 2026
See all posts