The communities of Milford and Hopkinton are trying to help the families who lost their homes - as well as the young couple who lost two daughters - in Wednesday's apparent natural gas explosion that leveled a multi-family house.

The funeral Mass for sisters Violet and Iris Carey is set for 10 a.m. Monday at St. Mary's in Milford. Visiting hours are from 2 p.m. to 4 p.m. and 7 p.m. to 9 p.m. tomorrow at Buma-Sargeant Funeral Home in Milford.

Investigators are still trying to determine what caused the apartment house to explode at 1:30 a.m. Wednesday. A stove, a furnace, gas meters and piping from the home have been relocated to the state fire marshal's complex for thorough testing.

A contractor will be hired to conduct tests to determine if the gas delivery system may have failed, fueling the fatal blast, said Fire Marshal Stephen D. Coan.

Residents reported hearing a whistling or rattling sound coming from the basement prior to smelling the odor of natural gas that forced most of the residents out of the building before it was blown to bits.

Meanwhile, donations to assist Tara and Heath Carey with the burial expenses for their two daughters, ages 4 and 5, can be sent to The Violet and Iris Carey Fund, care of Fleet Bank, 209 E. Main St., Milford, Mass., 01757.