Updated - 2/22/15

The gruesome crash involving a 15-year-old pinned under an MTA bus, resulting in the driver's arrest, had union officials calling for "extreme caution" on the road.

The crash in Williamsburg occurred Friday around 8:45 a.m. when Francisco DeJesus, 58, with nearly three decades of experience at the MTA, made a left onto Grand Street, from Union Street. The bus hit 15-year-old Jiahuan Xu, who was walking on the Grand Street crosswalk with the pedestrian signal, according to police.

That arrest, the second of a bus driver since December, angered the union, who said the city's Right of Way law enacted under Mayor Bill de Blasio's Vision Zero street safety program, was meant for "deliberately reckless drivers," Transport Workers Union Local 100 chief John Samuelsen said in a statement. JP Patafio, the vice president of TA Surface at the union, said the word is out to MTA bus drivers be extra careful.

"They're the safest drivers mile-for-mile," Patafio said. "But now that you can be arrested and thrown in jail right after an accident of that severity, I'm telling them, drive with utmost care."

The NYPD arrested 17 people under the new "Right of Way" law, including six MTA bus drivers.

DeJesus was arrested and put in a cell -- "humiliating," as Patafio put it -- given a desk appearance ticket and charged with failure to yield and exercise due care.

Xu's family told CBS New York on Friday they were worried that she may lose a leg and that they back the law that led to DeJesus' arrest.

"My little girl did nothing wrong, and now she's scared to death," her father Jingxiang Xu told CBS New York.

Samuelsen, the union president, called on bus drivers to stay put until a pedestrian on the crosswalk is on the sidewalk.

"Do not move your bus until all is clear," Samuelsen wrote. "If you do not make your schedule, so be it. If traffic backs up as you await the ability to make an unquestionably 'safe' left turn, so be it. If the bosses are displeased, so be it."

The arrest opened a rift between union officials and rank-and-file bus drivers and safe street advocates who on Friday celebrated the driver's arrest. The MTA, for its part, defended itself on adhering to the city's new Vision Zero policies, touting new training and monitoring programs for drivers and testing a warning sound for pedestrians when buses turn and for drivers to check on people crossing.

The TWU’s Patafio said the union backs Vision Zero.
 
“We're going to still push design of the streets, dedicated left-turn signals, and dedicated bus lanes,” Patafio said. “We want to see street design decrease competition on the streets.”

Paul Steely White, executive director of Transportation Alternatives, said he welcomed the TWU's stance.

"They seem to be placing a new found primacy on driver accountability, driver care, going to great lengths to make sure they're yielding to pedestrians," he said.

He added that the safe streets community had "touched a nerve," part of which is due to the difficult conditions MTA bus drivers face. He said bus drivers have a challenging job unlike drivers in other cities with the amount of people and bicyclists on New York streets.

"I think the bus driver being charged and held accountable to the laws are absolutely right," he said. "Should the bus driver have been hauled off in cuffs? Probably not."