The present work employs acoustic emission (AE), a secondary monitoring tool in synchronisation with synchrotron X-ray imaging to detect and localise cracking during the process. X-ray radiographs were used as ground truth to correlate the bulk AE signals. Our results reveal the formation and propagation of cracks in-situ under different processing conditions, that can be efficiently tracked using AE. The deciphering of the AE signals with mode decompositions showed that hot cracking during laser processing could be clearly distinguished from the process emissions, i.e., laser-matter interaction, and could be traced temporally and spatially. Overall, the current research showcases the capabilities of bulk AE sensing as a process monitoring tool for detecting and localising crack in-situ during PBF-LB process.