lvm lost one pv.

hello,all.
I have a vg named mirror.include 3 pv,/dev/sdb,/dev/sdc,/dev/sdd.
and have a lv on the vg named mirror1.I haved format the mirror1 into ext3. but now I lose the /dev/sdc.how can I restore the data on the /dev/sdb and /dev/sdd?