What symptons have you had?
Excessive smoke? Had you topped up the oil before hand?
If it's definately the turbos then......
Oil supply/starvation problems?
Were they both new/used/recon? It could be just bad luck that you had two nearly dead turbos.
Is your car set up properly? Excess heat can help kill turbos if you're running lean, normally tho you get det first and the ecu looks after you.