NEW YORK — The crisis-management playbook is pretty simple: Get ahead of the story, update authorities and the public regularly, accept responsibility and take decisive action. Crisis-management experts say that until Wednesday, Facebook was 0-for-4.

Facebook’s two top executives, CEO Mark Zuckerberg and chief operating officer Sheryl Sandberg, went radio silent after news broke last Friday that political consulting firm Cambridge Analytica may have used data improperly obtained from roughly 50 million Facebook users to try to sway elections, including the 2016 White House race.

It was not until five days after the scandal erupted that Zuckerberg spoke up.

Meanwhile, some Facebook users have been leaving the social network or mulling the possibility , and Facebook’s stock is down 9 percent since Friday.

Facebook’s handling of the growing public-relations crisis is remarkable in that one of the world’s biggest companies seems not to be playing by well-established crisis-management rules.