Nashville, TN – Carbon monoxide poisoning was the apparent cause of death Friday of a Nashville man and two sons.

Officers were dispatched to 625 S. Mill in Nashville about 11:15 a.m., where they found the three bodies in an outbuilding behind the residence. The victims had been staying in the outbuilding temporarily while the house was being renovated. A gasoline-powered electrical generator was being used to power the outbuilding and had been running all night, Nashville Police Chief Amy Marion said in a statement.

The names of the youths, ages 14 and 13, were not released by authorities.

The bodies were taken to the Arkansas State Crime Lab for autopsies.

Gasoline-powered generators emit lethal carbon monoxide and authorities caution that they should not be used in or near confined spaces.