Investigators in Tennessee are searching for a missing mother of four who disappeared four days ago.
Karen Johnson Swift, 44, was last seen by her husband at her home in Dyersburg at approximately 1:30 a.m. on Oct. 30. Dyersburg is about 75 miles northeast of Memphis.
Swift's car, a white 2004 Nissan Murano, was found less than a mile away with a flat tire. The car has been sent to a crime lab in Nashville for forensic testing.
The Dyer County Sheriff's Office is "aggressively investigating" her disappearance, according to a statement from Sheriff Jeff Box. Agents from the Tennessee Bureau of Investigation, Tennessee Highway Patrol and the FBI's Violent Crimes Task force have been searching for Swift with ground searches, helicopters and bloodhounds.
Authorities suspect foul play in Swift's disappearance.
Swift's father Gary Johnson, 67, told ABCNews.com that the family is "worried to death" and that Swift's four children—two boys and two girls—are devastated.
"She had never missed a day since they can remember that she wasn't there to wake them up at 6 a.m.," Johnson said.
Swift's two sons are in college and her daughters are 7 and 9 years old. Johnson said his youngest granddaughter "just cries" and "won't hardly eat."
"She is a great mom and works hard," Johnson said. "She's a sweet person, real nice, gets along with everybody."
Johnson described his daughter as a talented landscaper with a devoted group of customers in her hometown of Walnut Ridge, Ark., where her parents live. Swift was scheduled to go to Arkansas today to do some landscaping.
Swift's mother last spoke to her on Friday. "She sounded excited about coming down here and working," said her father.
He imagines that his daughter got a flat tire and thought she'd just walk home when something must have happened to her.
"She usually runs about three miles a day. She's in real good shape," he said. "She probably figured she'd be able to get home in 10 minutes [on foot]."
Swift is in the process of getting divorced and her husband has been interviewed by police and is not considered a suspect.
Dyer County Sheriff Jeff Box did not immediately respond to requests for comment.
Swift has blonde hair and green eyes. She is 5 feet 5 inches and weighs 138 pounds. Investigators are asking that anyone who may recall seeing Swift or has any information regarding her location contact the Dyer County Sheriff's Office at 731-285-2802.