Unless the death is related to the property itself, the owner does not have a duty to disclose it. A property defect that caused an occupant to fall to their death might be an example that is required to be disclosed. In fact, some types of deaths are protected events under Federal law (bless Washington) that cannot be disclosed.
For example, you cannot inquire and we cannot answer if a death occurred to someone with HIV. I disagree with the principle this prohibition reflects, but we must follow the law.
I disagree with it, because no one really knows to an absolute medical certainty that it is unequivocally safe to reside in a house where a virus was carried by an occupant. Imagine the virus were Ebola - the public would be outraged if owners and agents hid that fact. But because there is so much pressure to accept a disease commonly transmitted sexually, the jokers in Washington outlawed disclosing it. To me it is a national disgrace.
As to other types of deaths, records of murders and manslaughter are not typically indexed by address. The police blotter may have some information, but Bruce is probably right - ask the neighbors. They often know things that aren't their business and are willing to blab it to anybody who asks. You can investigate the neighborhood crime statistics on several websites, but past performance is no guarantee of future events.