Various factors stacked up and caused this crisis.
Tips
usage
Used in physics (wave superposition 波的叠加), in image/graphics work (layer overlay), and figuratively for compounding factors or effects. The figurative use ('factors A and B 叠加 lead to X') is increasingly common in news writing.
memory
叠 (dié, to fold/pile up — same character as 折叠 'fold up' and 重叠 'overlap') + 加 (jiā, to add). Together: 'pile + add' = stack on top.