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

Lawmakers Raise Doubts About Hochul’s Insurance Proposal

The governor's Uber-backed insurance plan is leaving state lawmakers unsure of its effect on crash victims and high auto premiums.

February 27, 2026

‘Broadway Vision’: City Will Revamp Six More Blocks By 2031

The facelift will cost more than $150 million.

February 27, 2026

Mamdani Falls Short of Campaign Pledge to Expand Open Streets Funding Amid Budget Crunch

The mayor's proposed budget does not expand Open Streets — and raises lots of questions.

February 27, 2026

Friday Video: Why Everyone Drives SUVs

Rollie Williams at Climate Town is back, this time explaining the "light-truck loophole."

February 27, 2026

Friday’s Headlines: Undermined at Every Turn Edition

Does the mayor run NYPD and FDNY, or is it the other way around? Plus more news.

February 27, 2026

Mamdani’s FDNY Spews Anti-Street Safety Talking Points at Bizarre Council Hearing

FDNY and DOT were at cross-purposes during a bikelash Council hearing.

February 26, 2026
See all posts