Twitter is banning all outside visitors from the company’s headquarters in San Francisco amid concerns over the spread of the novel coronavirus. Facebook also announced on Monday that it is banning external visitors, including friends and family of employees, from its company office due to coronavirus fears. “Out of an abundance of caution and because the situation is evolving so rapidly, Twitter is implementing a mandatory global business travel restriction for our employees, canceling all upcoming events, and pausing external visitors to company offices, effective immediately,” God-is Rivera, global director of culture and community for Twitter, wrote in a statement. She added that the #BlackTwitterLive live-streaming event that was set to take place on Tuesday will be postponed. The event planned to “bring together some of the most powerful voices from #BlackTwitter to discuss the impact and influence of this dynamic community.” Rivera said that the company “has been monitoring” the coronavirus outbreak, adding that “there is no higher priority for us than the health and safety of our employees and guests.”