Firefighters are investigating what caused a house fire Monday morning in a Tulsa neighborhood, authorities say.

The Tulsa Fire Department responded to a home at around 3 a.m. near East Apache Street and North Lewis Avenue.

Investigators say it appears the fire began outside the house, and flames spread into the roof.

Firefighters say a classic military-type vehicle was parked nearby and sustained major damage as a result of the fire.

TFD said when firefighters arrived, the homeowner was outside and was not hurt.