Last evening, Facebook, Instagram, and WhatsApp went down for a few hours across many parts of the world. The rare global outage of Facebook, Instagram, and WhatsApp which lasted for six hours cost the owner Mark Zuckerberg a whopping $6 billion.

According to reports in international media (Bloomberg), the outage caused Facebook's share price to plummet by five percent. With this, the Facebook CEO slipped from fourth spot to fifth-richest person as his net worth dropped to approx $121billion.

Zuckerberg fell one slot on the Bloomberg Billionaires Index behind Bill Gates, who previously held the fifth position. On Monday (October 4), the social media services went down at about 16:00 hours GMT with users beginning to gain access to the sites at around 22:00 hours GMT.

After the services were back, Zuckerberg in a Facebook post sought an apology for the inconvenience caused due to outage. I know how much you rely on our services to stay connected with the people you care about, he said.

WhatsApp also apologised to the users and thanked them for the patience during the outage. Zuckerberg lost about $19 billion of wealth since September 13, when he was worth nearly $140 billion, according to the index.