A longtime children’s librarian killed in a Fenway bicycle crash Friday afternoon was remembered by her husband and friends for the passion she showed in life — from leading children in a library sing-a-long to facing arrest as she fought to protect a woodland from development.

Paula Sharaga, 69, of Cambridge worked in public libraries in Brookline and Holliston, and earlier was a nursery school teacher, said her husband, Eric Zinman. They were together for 25 years, he said.

“She’s a beloved person, everybody loved her,’’ Zinman said, fighting back tears. “She had a lot of light in her eyes and in her smile.’’

Sharaga was riding a bicycle when she was struck around 1:20 p.m. Friday by a cement truck on Brookline Avenue at Park Drive, authorities said. Sharaga was later pronounced dead at Brigham and Women’s Hospital.

The cement truck’s driver, a 67-year-old Salem man, was taken Friday to Beth Israel Deaconess Medical Center for evaluation, authorities said.

The investigation was ongoing as of Saturday afternoon, and no charges were filed, according to David Procopio, a spokesman for the Massachusetts State Police.

The collision reconstruction process continued on Saturday and detectives will compare those results with witness statements and other evidence, Procopio said in an e-mail.

A preliminary investigation indicates the truck was stopped at a traffic light on Brookline Avenue, and when the light turned green, it moved forward. Sharaga was cycling in the intersection and came in contact with the front end of the truck, authorities said.

A State Police trooper and three passersby worked to provide aid to Sharaga at the scene, authorities said.

On Saturday morning, pedestrians and the occasional bicyclist queued at crosswalks while traffic roared through the intersection. Peter Cheung sat on his bicycle as he waited to cross Brookline Avenue.

Cheung organizes local “ghost bike’’ memorials for bicyclists who have died in traffic crashes — each tribute includes placing a bicycle painted white near the scene of the crash. He anticipates that Sharaga will be honored with a similar memorial next weekend, he said.

Cheung said he was already concerned about his safety in the area before the crash. The city needs to slow down traffic and install protected bicycle lanes to help improve conditions for riders, he said.

“Of course we’re more nervous [after the crash]. It’s a lot of traffic. It’s not safe for bicyclists at all,’’ Cheung said.

Speaking to reporters Saturday at an event in Brighton, Boston Mayor Martin J. Walsh said he first learned about the crash from news reports.

“Any time you see something like that . . . [it’s] just a sad situation,’’ he told reporters Saturday.

The city has worked with the state in making investments to reduce traffic fatalities over the past five years, he said. But more needs to be done to improve the infrastructure for bicyclist and pedestrian safety in Boston and across the state, he said.

Speaking generally, Walsh also said that motorists, bicyclists, and pedestrians all must be more careful while traveling.

“We all have to be more aware of what is happening on the road,’’ Walsh said.

In Brookline, Sharaga was known for being a talented singer and guitarist who would lead children in sing-alongs, said the town’s library director, Sara Slymon, in a phone interview. As a librarian, she had a wide knowledge of the library’s book collection, and would feel a pang of sadness if a worn-out book had to be pulled from circulation.

“She just seemed to have an absolute passion for it,’’ Slymon said.

Sharaga worked for almost 20 years at the town’s Coolidge Corner Library branch, which was closed Saturday in the aftermath of the tragedy. The branch will also be closed Sunday, Slymon said.

The library’s staff were notified individually by phone about Sharaga’s death, and grief counselors will be available all weekend to help library staff deal with the loss, she said. Staff were shocked and deeply saddened by Sharaga’s death, she said.

“I very much admired Paula’s passion for life and service,’’ Slymon said. “I will miss her terribly.’’

Sharaga was also active as a political progressive, supporting local lawmakers like US Representative Ayanna Pressley of Boston and state Representative Michael Connolly of Cambridge. Connolly, who met Sharaga in 2012, remembered that she and her husband invited him into their home while he was canvassing the city.

“She was a dear friend to many people in the Cambridge community, and I’m just heartbroken about this tragic loss,’’ Connolly said in a phone interview.

Sharaga had a strong moral compass, he said, which extended to her advocacy for the environment.

In 2014, she was arrested by Belmont police during an act of civil disobedience when she and other advocates protested development in the Silver Maple Forest, which spans parts of Belmont, Cambridge, and Arlington, according to Connolly and Wicked Local Cambridge, which reported on the arrests at the time.

“She just saw it as her duty to live for her values,’’ Connolly said. “That was the kind of person she was.’’

On Facebook and Twitter, Sharaga posted images of herself wearing a PERSIST T-shirt, as well as support for immigrants and environmental causes. On her birthday last October, she asked for donations to the Massachusetts Peace Action Education Fund, which promotes denuclearization and other causes.

Cole Harrison, the executive director of Massachusetts Peace Action, said Sharaga had been an active member of the group since the 1980s. She also led its Boston Downwinders group, which advocates for the closure of the Pilgrim Nuclear Power Station in Plymouth, he said in a phone interview.

Just a few hours before the crash, Sharaga was in Peace Action’s offices in Cambridge. Harrison remembered helping her with the Downwinders’ e-mail list before she left around 12:10 p.m. Friday, he said.

She was a “spark plug’’ who worked tirelessly for what she believed, he said.

“She just felt you have to make a difference,’’ he said.

Danny McDonald of the Globe staff contributed to this report. John Hilliard can be reached at john.hilliard@globe.com.