BRISTOL, Tenn. -

A fire that forced families from their apartment started in the first floor stairwell of the apartment building on Windsor Avenue in Bristol, Tennessee.

Investigators say they have collected evidence that will be sent for lab testing.

Units from both Bristol, Tennessee and Bristol, Virginia were called to an apartment building fire on Windsor Avenue in Bristol, Tennessee.

909 Cavalier Apartments is an old house that has been converted to apartments.

When fire crews arrived around 7:30 Monday afternoon, flames were shooting out of the top of the building.

Four families live in the apartment, but we are told nobody was home when the fire started.

Those four families are now homeless because of this fire.

Firefighters tell us the blaze was under control by 9:00 Monday night.