From Longman Dictionary of Contemporary Englishfall into something phrasal verb1 to move somewhere quickly by relaxing your body and letting it fall on something She turned and fell into his arms. We fell into bed, exhausted.2 to start doing something by chance I fell into the job really. → fall→ See Verb table
Examples from the Corpus
fall into • I'm just going to go home and fall into a hot bath.• She fell into bed the moment she got home.