The 8th October 2023 registered a uphill lake dam collapse at Mbankolo (Cameroon), subsequent to heavy rains. In this study, a block theory approach was performed to investigate the potential thorough triggering causes of this dam collapse. Block theory method provided graphical processes to analyse rock block stability under gravity and water pressure as the main forces. The results achieved with local discontinuity measurements suggest that the basement joint network might require at least about 6° friction angle on each joint to maintain the stability of the blocks involved in the stability of the dam. During the rain, water pressure might have decreased the friction angle up to less than about 6°, hence the move of at least one basement potential or key block and the collapse of the dam. However, soil mechanic and civil engineering approaches will be usefull to draw the final conclusions.