Due to means 'caused by,' and owing to means 'because of.' Nouns are due to something, and verbs happen owing to something. For your consideration:

'The delay was due to the huge, city-trampling Puff 'n Stuff man.'

'We were late owing to the huge, city-trampling Puff 'n Stuff man.'

"The prepositional use of owing to is some 150 years old, but of a similar use of due to there is not a vestige in the OED (1897); in the 1933 Supp. it is said to be 'frequent in U.S. use', and in 1964 the COD tersely dismisses it as 'incorrect'.

- Fowler