SPRINGVILLE, Utah (CNN) -- There were no signs of trauma, no clues of any violence or foul play.



So investigators are trying to determine how five family members died in a Utah home over the weekend.



Officials identified the deceased relatives as father Benjamin Strack, 37; mother Kristi Strack, 36; son Benson Strack,14; daughter Emery Strack, 12; and son Zion Strack, 11.



Another son of the couple found the bodies on Saturday night, the Springville Department of Public Safety said.



Preliminary autopsy results have ruled out any sort of violent assault.



"The Medical Examiner has indicated that the next step is to continue the investigation through analysis of blood samples to determine what may have caused the deaths," the Springville DPS said.



All five bodies were found in one bedroom of a duplex, CNN affiliate KUTV reported.



Firefighters entered the home wearing special equipment to test for carbon monoxide, but there was no indication of a buildup of the odorless poisonous, gas, Springville Police Lt. Dave Caron said.



That test does not necessarily rule out carbon monoxide, however, as the doors had been opened and a storm had brought wind and rain capable of clearing the gas, Caron said.



The family had three pets -- a kitten, a full grown cat and a ferret -- who all survived, he said.



Again, the survival of the animals cannot confirm whether there was poisonous gas in the house at one point or not.



Police are awaiting the lab results, Caron said.



