AUBURN, Wash. -

Authorities say 16 homes were evacuated in a city south of Seattle after methane gas was found in soil samples there.
   
Kent Regional Fire Authority spokesman Kyle Ohashi tells The News Tribune that Puget Sound Energy crews discovered traces of gas in the soil while taking routine samples in Auburn Thursday evening.
   
The fire authority's hazardous materials team determined that the gas was methane. Crews also found traces of methane in homes in the neighborhood.
   
Families from 16 homes were kept warm on a bus until fire officials determined it was safe for them to return home at about 6 a.m. Friday.
   
Ohashi says the source of the minor methane presence is unknown.
   
The problem will now be turned over to Auburn and the state Department of Ecology.