Why do shipwrecks occurred? Because of shallow faith. Like the seed sown among stones they allegedly believe as first, and with joy, but when tribulation or persecution arises because of the word, immediately they stumble. Matt 13:5,21 Thus traveling on shallow waters they end up shipwrecked. Or like a train they get "off track".
Others get shipwrecked by not taking heed to their conscience which corrupts it, causing it to lose its effectiveness in directing the person, so he ends up dashed against the rocks along the shore, not keeping to the course. Or one may have such an effect on the conscience of others. For it is written that "when you thus sin against the brethren, and wound their weak conscience, you sin against Christ."1Cor 8:12 which causes them to stumble.