Hallie Thomas was a physician and one of the characters of Chicago Fire.
Hallie had an on-and-off relationship with Matthew Casey for 8 years. They were engaged, however she broke it off. They later reconciled when Casey asked if they could start fresh. Later, Hallie informs Casey that she doesn't want to have children. Because of this, they break up again and she moves to South America.
When Hallie comes back near the end of Season 1, she and Casey reconcile. They realize how much they missed each other. Hallie is murdered after witnessing a drug operation at a clinic she worked at during the episode "Leaders Lead", an event which devastates Casey.
Hallie was engaged to and had a relationship with Matthew Casey for eight years, during which they separated and later reconciled.
At the end of Season 1, the clinic in which Hallie was working caught fire. She was found unconscious inside of a locked security cage by Casey and Severide. After being pulled from the building, she was transported with CPR in progress to Chicago Med, where she was pronounced dead. During the course of the subsequent investigation, Antonio Dawson tells Casey that Hallie was murdered when she was struck on the back of her head prior to the fire. It was later revealed that the person responsible was Timothy Campbell, who was later fatally shot by Voight
(To Casey about Mills and Dawson) "That sneaky little bastard" 1x21
|Season 1 Appearances|
|"Pilot"||"Mon Amour"||"Professional Courtesy"||"One Minute"||"Hanging On"|
|"Rear View Mirror"||"Two Families"||"Leaving the Station"||"It Ain't Easy"||"Merry Christmas, Etc."|
|"God Has Spoken"||"Under the Knife"||"Warm and Dead"||"A Little Taste"||"Nazdarovya!"|
|"Viral"||"Better to Lie"||"Fireworks"||"A Coffin That Small"||"Ambition"|
|"Retaliation Hit"||"Leaders Lead"||"Let Her Go"||"A Hell of a Ride"|