Investigators are out on Lake Powell this morning researching what caused a deadly houseboat explosion last night.  

San Juan County sheriff’s deputies and National Park Rangers suspect a generator exploded as it was being started on a privately-owned house boat late Wednesday night. 

The explosion killed a 52-year old woman and seriously injured four other people, who were flown to area hospitals.

They were on vacation as the boat sat in Crystal Springs Canyon, on Lake Powell, about five miles north of the Bullfrog inlet on the Utah side. Investigators have not released the names of the victims.