A dwelling fire on Friday that claimed the life of an elderly North Baltimore man and injured his son remained under investigation yesterday by the city Fire Department.

William Campbell Jr., about 70, died of burns Saturday at Johns Hopkins Bayview Medical Center, while his son, William Campbell III, 47, was released after treatment, authorities said.

The fire broke out about 6:30 a.m. Friday in their two-story brick rowhouse in the 1300 block of Weldon Ave., in the city's Medfield neighborhood.

The Campbells' pet dog was revived by firefighters and taken in by Jo Anne Palmore, a neighbor who lives three doors away.