RENTON, Wash. -- A 52-year-old woman has died after wielding a machete against her neighbors and then starting a fire inside the duplex she shared with them.

Police spokeswoman Penny Bartley said officers received a call just before 8 p.m. Monday from a woman who said her neighbor was chasing her down the street while swinging a knife and a machete.

The caller told police she had just arrived home with a small child when her neighbor came at her with the weapons. The woman managed to get away and call 911. She was not seriously injured.

When police arrived, the armed woman ran into her home. Minutes later, officers saw fire and smoke coming from inside. Police believe the woman started the fire that ultimately killed her. She was found dead inside.

Neither investigators nor witnesses knew what to make of the bizarre series of events on Monday night.

Neighbors said they've been concerned about the woman's mental health for the past several weeks, but never thought she would pick up a machete.

Bartley said police had recently responded to other reports of the 52 year old being armed with a knife.

Some witnesses said police officers had fired tear gas into the house. But police said the only thing they fired was a round of bean bags, a non-lethal projectile, to let out the gas and smoke from the house.

The dead woman was not immediately identified, and the exact cause of the fire is under investigation.