Firefighters battle house fire in Apex

APEX, NC (WTVD) -- An Apex family is crediting a smoke alarm with awakening them Wednesday night as their Johnson Pond Road home went up in flames.

Four people along with two dogs escaped safely - but a third dog did not survive.

Ammunition in the house caused some explosions, firefighters said, but that was not the root cause of the fire.

The homeowner told ABC11 there were oxygen tanks in the home because an elderly couple lived there.

The homeowner said the house quickly filled with smoke.

Firefighters from multiple departments responded about 9:30 p.m.

The fire's cause remains under investigation.