SNOHOMISH, Wash. -- Fire investigators are sifting through charred remains of a mobile home in Snohomish to learn if a fire that killed four people there was intentionally set, reported KIRO 7 Eyewitness News.

Flames destroyed the home at the Snohomish Mobile Home and RV Park early Tuesday, killing 25-year-old Petra Montano Reynaga, her 28-year-old sister Maria Montano Reynaga and Maria's daughters, Ashley, 7, and Jarele, 3.

Loved ones of the victims gathered Tuesday night at Saint Michael's Church for a special Mass and spoke with KIRO 7 news reporter Monique Ming Laven.

Family members told Ming Laven that the women had moved into the mobile home last weekend and that the women though that buying their first home was important for their little girls.

The two women, who were originally from Jalisco, Mexico, have three brothers in the area who said they will be buried back home.

Investigators from the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Washington State Patrol remained at the scene late Tuesday collecting evidence.

Police said they will give an update on the investigation on Wednesday.