Georgia ? A bitter family dispute over property in north Georgia apparently erupted Friday when a 78-year-old man threw an explosive into a law firm that represented his son, causing a blast that killed the father and injured four people in the office.

The explosion blew out windows of the two-story, colonial-style house where attorneys worked, and some in the small blue-collar town of 30,000 felt vibrations from more than a block away.

Authorities identified the bomber as Lloyd Cantrell, a man known around town for wearing bib overalls and carrying a small Chihuahua. Over the years, Cantrell amassed several parcels of land in the area, and gave some of the property to his son.

His son had grown fearful of his father, though, and filed a lawsuit seeking to keep his dad off the property the son had been given, claiming the elder man stole tools, kicked down a door and was suicidal.