WEIPPE, Idaho (KLIX)-Authorities say a faulty electrical light fixture is the cause of a fire that claimed the lives of twin toddler boys in northern Idaho.

According to the Idaho State Fire Marshal, three-year-old twins John and Shawn Carr died in an early morning fire in Weippe on Feb. 21. Investigators arrived on scene at around 2 a.m. with the priority of locating the young children who had last been seen sleeping in the living room.

Authorities say the search effort was hampered by the collapsed roof and weakened floors. “This was one of the most difficult cases I’ve dealt with in my 35-year career,” said Idaho State Fire Marshal Knute Sandahl in a prepared statement. “After about 5 hours of searching the twins were found in the kitchen area. The tragic loss of these two boys impacted every State Fire Marshal investigator and first responder there and no doubt the entire community of Weippe. Our hearts goes out to the family of John and Shawn.”

Investigators say the mother woke up to smoke and alerted the father who tried to find the two children, but was pushed back by heat and smoke. Both parents made it out of the home. Investigators say they did not find any smoke detectors in the home during the investigation.