Can BIOS upgrade damage something?

[michalwd1979]

Hello,
While I never had a situation when BIOS upgrade went wrong I am wondering if it can damage something. For example I have a power failure/storm/nuclear explosion during upgrade and the server has been rebooted in the middle of writing new image to flash. Does anyone know what would happen then? 
Or maybe someone has already experienced such situation?
My system is PE2850 with gentoo linux and A07 Bios.

Thanks in advance
Michael W.