Nearly 250 people put down their bikes for a moment of silence for Tom Hollowell, a cyclist killed at 12th and Constitution Ave. NW on Sept. 24. (Jordan Pascale / WAMU)

Thomas Hollowell was a grandfather, a husband and a Smithsonian museum employee.

During the Thursday evening rush hour, his grandchildren, wife, co-workers, friends and strangers — more than 250 in all — rode their bikes from Farragut Square to the place where he died, to honor his memory.

For more than 15 minutes, cyclists and pedestrians dressed in white put their bikes down in the middle of the intersection of 12th and Constitution Avenue where Hollowell was hit and killed by a driver running a red light on Sept. 24.

The driver sped away from the scene and has not been identified by D.C. police. The crash is still under investigation. Three banks of cameras are pointed at the intersection, but police haven’t released a photo or asked the public to help find the driver of the dark sedan.

Hollowell biked to work in all kinds of weather for more than 20 years. He worked as a database manager for the Smithsonian National Museum of Natural History but also researched ecology and conservation of mangroves in Guyana.

His wife helped affix a sign to a white ghost bike, a longtime tradition in the cycling community to mark where cyclists have been killed. “A cyclist was killed here,” the black sign read.

The almost 15-minute moment of silence was only broken by the honking of nearby cars and sobbing of the memorial’s participants.

Rachel Maisler, an active member of the bike community, organized the ride. It’s the fourth she’s had to plan in the last four months.

Ride organizers say they want the city to put protected bike lanes along the National Mall, dedicated right and left turn traffic lights on Constitution Avenue and Independence Avenue and red light and speed cameras at the 12th Street tunnel, and every major intersection along Constitution and Independence avenues.

Advocates also want the D.C. auditor to look into the city’s efforts at implementing Vision Zero, the initiative that aims for zero traffic fatalities by 2024. Since the effort began in 2016, traffic fatalities have increased year over year. Advocates say the city isn’t meeting its goals fast enough to save lives.

Seven people — cyclists, scooter riders and pedestrians — have been killed by a driver since June 23.

Malik Habib was killed riding his bike on H Street Northeast on June 23. Dominique Antonio Lewis was killed riding a scooter on Shippen Lane Southeast on July 4. Jeff Long was killed riding his bike on M Street Northwest on July 7. Sherron Pressley was killed while walking on Kenilworth Avenue in a hit and run on Aug. 30. Carlos Sanchez-Martin was killed riding a scooter in Dupont Circle on Sept. 21. Hollowell was killed Sept. 24. Ramona Williamson was killed while walking on Central Avenue Southeast on Oct. 2.

This story originally appeared on WAMU.