By Jim Melwert, Dray Clark

WARMINSTER, Pa (CBS) — A 89-year-old woman was killed in the crossfire during a police standoff in Bucks County.

The incident started Tuesday afternoon with a domestic disturbance at the Jefferson on the Creek apartment complex along the 600 block of East Street Road in Warminster.

Then around 7:30 p.m., another call came for shots fired from the same apartment.

As police approached the apartment, Warminster Township Police Chief Michael Murphy says they came under heavy gunfire.

“During the course of exchange of gunfire, the downstairs neighbor of the gunman, a 90-year-old female was struck by gunfire, and died of her wounds at the scene. The Warminster Police Department wishes to express our deepest sympathy to the family of the deceased victim,” Murphy said.

They’re not releasing her identity. She was pronounced at the scene, and taken from the building by SWAT around 10 p.m.

Police say the man, identified as 49-year-old Andrew Cairns, gave himself up around 2:45 Wednesday morning, nearly seven hours after this all started. He’s currently facing aggravated assault charges.

So far, there is no word on what started this, or why the man fired shots at police and why he locked himself in, but after a tense night, police were able to take the man into custody.

Many neighbors were confused and concerned.

“The officer yelled at me to get in and you hear these blasts,” said Renee Sherin, a neighbor.

“I tried to go to the store, they told us to go back in the house and pretty much lock ourselves in and cut the lights off,” said another neighbor.

Police returned to the apartment complex Wednesday looking for more evidence.

At the top of their agenda is trying to determine whose bullet killed the 89-year-old woman.