A Deed of Power of Attorney executed by 5 principal regarding their joint family property to one Agent on 25.6.1996. One of the Principal died on 19.4.1999. The Power of Attorney holder (agent) sold the entire property as power given by the above said principals on 20./3.2006. Whether the power of attorney holder exeucted a sale deed is valid or not? whether the one of the principal died the entire deed of Power of attorney invalid or not?