Matthew 24: 37 - 44
37 As were the days of Noah, so will be the coming of the Son of man.
38 For as in those days before the flood they were eating and drinking, marrying and giving in marriage, until the day when Noah entered the ark,
39 and they did not know until the flood came and swept them all away, so will be the coming of the Son of man.
40 Then two men will be in the field; one is taken and one is left.
41 Two women will be grinding at the mill; one is taken and one is left.
42 Watch therefore, for you do not know on what day your Lord is coming.
43 But know this, that if the householder had known in what part of the night the thief was coming, he would have watched and would not have let his house be broken into.
44 Therefore you also must be ready; for the Son of man is coming at an hour you do not expect.

EWTN