The 'most serious IT outage the world has ever seen' sparked global chaos today - with planes and trains grounded, medical facilities impacted and businesses including banks, hotels and casinos shutdown.
The blackout has been affecting Microsoft apps and services for hours, with the travel and medical industries amongst the worst hit.
The issue was caused by an update to Crowdstrike's 'Falcon Sensor' software which crashed, crippling Microsoft computers.
