Michele Refford walked up and down the three blocks of demonstrators Tuesday morning, her cell phone outstretched. On the other end of a FaceTime call was her daughter, Becca, recovering from surgery in a hospital bed at Thomas Jefferson University Hospital.

Becca cried as she saw the dozens of people who had lined 13th Street in Center City. They were forming a human barrier between the cycling and driving lanes, advocating for protected bike lanes just blocks from where Refford was hit by a box truck Friday morning.

"She was excited to overwhelmed," Michele Refford said.

"The support system is incredible," said Becca's 22-year-old brother, Matthew Refford. "No one knows my sister personally. They are all looking out not only for Becca but also for themselves, which is awesome."

Becca Refford, a 24-year-old web designer who lives in South Philly, was on her way to a medical appointment when she was struck on the 1200 block of Pine Street. A truck had been making a right turn from 13th Street onto Pine, which does have a bike lane, when it hit her. The driver is cooperating with the investigation, authorities said.

Becca's accident occurred less than three weeks after Emily Fredricks, a 24-year-old pastry chef, was killed in a bike lane on 11th Street on her way to work.

The second crash further fueled activists, who had also formed a human bike lane after Fredricks' death. Philadelphia has about 200 miles of bike lanes — 2.5 of which are protected by some physical obstacle, like flexible posts — but bike advocates say that's not nearly enough and city officials need to implement changes more quickly to protect bikers.

Mayor Jim Kenney has said he wants 30 miles of protected lanes by 2022. And after Fredricks' death, he announced the city will next year add flexible posts as a barrier to the bike lanes on South Street from 21st to 27th Streets, as well as from South Street to Lombard along 27th.

Around 8 a.m. Tuesday, demonstrators — some wearing helmets and bike gear — once again formed a human chain, yelling to cyclists: "This lane's for you."

Many bikers responded with thank yous and high fives. Some passing drivers honked in a show of support.

Lizzie Rothwell, 37, of South Philly, held a sign that said, "Please don't park in our lane." Beside her stood her 4-year-old son, Luke Beauregard, in a multi-color bike helmet.

Rothwell said she considered coming out by herself Tuesday morning, but Luke insisted on joining her before school.

Whenever the weather permits, Rothwell said she bikes Luke to school, from their home at 7th and Wharton streets to his school at 18th and South.

When Luke was born, it was a big decision whether she would continue biking. However, until around 2014, she said she felt the city was actively making improvements to conditions for cyclists.

She is disappointed, she said, to see lack of progress.

"Bikers have started to talk," said James Gitto, 26, of South Philly. "Most people feel unsafe."

Gitto and fellow event organizer Leigh Goldenberg encouraged Tuesday morning's demonstrators to take concerns to the mayor and city council.

Gitto said it has been frustrating to see resistance to protected bike lanes from those who want to use the bike lanes as loading zones.

As the protesters moved from the street to the sidewalk around 8:30 a.m., they began to disperse. Jake Liefer, 32, of South Philly, stayed for a few minutes to talk with Gitto when he noticed something.

"Oh," he said, "someone's already parking in the bike lane."