This is stated in a message posted on the Las Vegas fire service on Twitter.

8AM UPDATE: All agencies, @LasVegasFD Fire Investigators, @LVMPD Homicide & CSI & @CC Coroner investigators on scene investigating incident, this is STANDARD PROCEDURE for any fatal fire in @CityOfLasVegas. Total numbers now 5 fatalities, 13 injured, @RedCrossUtahNV 23 displaced. pic.twitter.com/2IFDf54z2D

- Las Vegas FireRescue (@LasVegasFD) December 21, 2019

All circumstances of the incident are being clarified.

A California congressional group previously proposed stricter safety standards for small passenger ships. This initiative was developed after the Conception boat burned and sank in September, killing 34 people.