It was an ordinary Wednesday on 4.04.2019. Except that at some point of the midday timeline an AS60280 belonging to Belarus’ NTEC leaked 18600 prefixes originating from approximately 1400 ASes.
Those routes were taken from the transit provider RETN (AS9002) and further announced to NTEC’s provider — RU-telecom’s AS205540, which, in its turn, accepted all of them, spreading the leak.