Note to Hillary Clinton, you may want to delete this tweet:

ALBANY — The allegation set social media ablaze, sowing shock and outrage as it went: Three black students at the University at Albany had been attacked on a city bus by a group of white men who used racial slurs as other passengers and the driver sat silently by.

The Jan. 30 episode, reported to the police, would draw hundreds of people to a campus rally against racism; an emotional response from the university’s president; and even the attention of Hillary Clinton, who condemned the attack on Twitter.

“We are shocked, upset, but we will remain unbroken,” one of the young women who reported the assault, Asha Burwell, said at the rally, on Feb. 1. “We stand here with strength because we value our worth as black women and as human beings in general.”

But only a few weeks later, what seemed to be the latest iteration of a now-familiar debate about race on campus — the protests, the anguished soul-searching, the calls for greater faculty diversity and administrative changes — has metastasized into a controversy of an even more scorching kind: the allegation, the authorities said, was a lie.

Surveillance videos did not support the accounts of the young women, Ms. Burwell, Alexis Briggs and Ariel Agudio. Neither did the statements of multiple fellow passengers. Rather than being victims of a hate crime, the authorities said, the women had been “the aggressors,” hitting a 19-year-old white woman on the bus.