WORTH TWP — The work of an unknown arsonist forced a father and his infant son, an 18-month old connected to life support machines because of a rare genetic disease, out of their home Thursday evening.

Soon after, authorities said, a family member collapsed and later died while rushing to save medical equipment from the house on rural Book Road.

It did not take state police long to rule the fire at Scott and Kayla Sniezek’s home about 5:30 p.m. was deliberately set.

Investigators, however, have not determined if the fire could have indirectly contributed to the death.

Family member, 58-year-old Dennis Morris, got there quickly to help. But he suffered cardiac arrest, authorities said, and was taken by ambulance to Butler Memorial Hospital, where he died later that night.

Police identified Morris as Scott Sniezek’s stepfather.

There are no suspects in the case.