Some (most) believe in their body/soul will be taken before the Apocolypse
The cited passage (1 Thess 4:15-17) itself says this will happen after the general Resurrection and on the Last day, not in a "secret" manner as Protestants believe. That alone should suffice to disprove the so-called "pre-tribulation rapture"
As for the true understanding, the bodies of the Catholic faithful who are on earth in that time will likely be translated after a painless death.
Objection 3. Further, when the Lord comes to judgment He will find some men living, as appears from the words of 1 Thessalonians 4:16
Reply to Objection 3. All men shall die and rise again: yet those are said to be found alive who will live in the body until the time of the conflagration