JEFFERSON CITY, Tenn. — UPDATE (6/19/19 at 10:40 a.m.):

The man accused in what authorities have called a 'deliberate crash' that killed a pregnant woman and her 2-year-old son now faces a third murder charge for the woman's unborn child, according to Jefferson City Police. 

Police Chief Andy Dossett said Wednesday that William David Phillips, 33, has been charged with another count of murder for the death of Sierra Wilson Cahoon's unborn child. 

An arrest warrant states 'a voice told him that he needed to go kill the meth addicts so he began driving very fast.' He reportedly told investigators that 'the voice told him that the baby stroller had meth in it so he intentionally drove into' Cahoon and her child. 

Police said he also struck a pedestrian, 61-year-old Tillman Gunter, along West Main Street before continuing less than a mile and hitting Cahoon and her child. He faces one count of attempted first-degree murder for that incident. 

The warrant said the victim told investigators he tried to get away from the car but Phillips 'kept coming'. He was treated at Jefferson Memorial for his injuries. 

Phillips is set to appear in general sessions court in Jefferson County on Friday at 9 a.m.

William David Phillips
William David Phillips
Jeff. Co Sheriff's Office

ORIGINAL STORY (6/18/19)

A woman who was inside a building that a vehicle crashed into says she is okay after authorities say the driver intentionally drove into it shortly after hitting another pedestrian, killing a pregnant woman and her young son Monday afternoon. 

RELATED: Pregnant mother & 2-year-old dead after driver deliberately ran over them, police say

The Jefferson City Police Department says 30-year-old Sierra Cahoon, her unborn child, and her 2-year-old son, Nolan, died near Sustainable Aquatics in Jefferson City. 

Police say the driver, 33-year-old William David Phillips, is charged with two counts of first-degree murder and one count of attempted first-degree murder.

William David Phillips
William David Phillips
Jeff. Co Sheriff's Office

Police say he struck a 61-year-old pedestrian along West Main Street before continuing less than a mile and hitting the pregnant mother and her child.

Katie McCord was working in one of the Sustainable Aquatics buildings when she suddenly felt water rushing over her. 

"So I got totally soaked, and then I looked back and I saw that there was a car," McCord said.  

McCord said she got out of the building with cuts on her hand and leg. She got stitches, and knows if she were just a few feet closer, she could have been worse off. 

"Maybe it hasn't really registered yet that that could've have killed me," McCord said. 

Owner John Carberry ran out to the scene minutes after it happened. 

"He penetrated the building after taking out a guy-wire on a telephone pole, sending a stop sign 300 feet through the air across the top of the building into one of the employee's cars here. [The vehicle] went through a block wall and went through a fish system that had 20 tons of water in it, and came to rest with his bumper about 10 feet past the entry point," Carberry said. 

He says his business is one of the world's largest producers of marine ornamental fish and believes tens of thousands of fish might have been lost in the crash, but he says the business will be okay. 

He's focused on the family and the tragedy they have to endure. 

"Nothing is comparable to the grief we feel for the family and community of Carson-Newman," Carberry said. "Just a young woman out with her son, pregnant, taking a walk on a sunny afternoon... and murdered."