Can a readied action occur during someone else’s triggering action?

@JeremyECrawford Can a readied action occur *during* someone else's triggering action (like, between their first and second attacks)?

— Seebs (@the_real_seebs) December 8, 2015

A readied action occurs immediately after its trigger. The trigger is an attack? You go after that attack. #DnD https://t.co/HlY7tfe9to

— Jeremy Crawford (@JeremyECrawford) December 11, 2015