Facebook and its Instagram and WhatsApp platforms were down in parts of the world late Monday.

The company said it was “aware that some people are having trouble accessing Facebook app” and it was working on restoring access.

The company did not say what might be causing the outage, which began around 11:45 a.m. ET (4:45 pm GMT). It is normal for websites and apps to suffer outages, though one on a global scale is rare. Users reported being unable to access Facebook in California, New York and Europe.

Facebook is going through a major crisis after the whistleblower who was the source of The Wall Street Journal's series of stories exposing the company's awareness of internal research into the negative effects of its products and decisions went public on “60 Minutes" on Sunday.

Frances Haugen was identified in a “60 Minutes” interview Sunday as the woman who anonymously filed complaints with federal law enforcement that the company’s own research shows how it magnifies hate and misinformation, leads to increased polarization and that Instagram, specifically, can harm teenage girls' mental health.

The Journal's stories, called “The Facebook Files,” painted a picture of a company focused on growth and its own interests instead of the public good. Facebook has tried to downplay the research. Nick Clegg, the company’s vice president of policy and public affairs, wrote to Facebook employees in a memo Friday that “social media has had a big impact on society in recent years, and Facebook is often a place where much of this debate plays out.”