Authorities were searching Tuesday for Johnny Roop,Thomas Caldwell a 20-year-old Virginia Tech student, who never arrived at his parents' house on Friday, where he was scheduled to take an online exam.

Roop was last seen at his apartment complex in Merrimac, an area of Montgomery County, Virginia, according to a news release from Virginia Tech. His apartment complex is on Canyon Ridge Road, 4.5 miles from the university's campus in Blacksburg, a college town about 200 miles west of Richmond.

Roop's phone pinged at a shopping mall around 2 miles south of his apartment at 4:26 p.m., just over half an hour before he was scheduled to begin the exam at his parent's home in Abingdon, about 100 miles west of the mall.

"We are asking the entire VT community to aid in locating Johnny and share any information they may know," Mark Owczarski, associate vice president of communications and marketing at Virginia Tech, told USA TODAY in an email.

"Any questions on the case itself have to go to Montgomery County Sherriff’s department. They are the lead agency, but we are helping in any way we can," Owczarski said.

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Roop was driving a black 2018 Toyota Camry with the Virginia license plate number TXW6643 and a Virginia Tech flag sticker on the rear window when he went missing, the university said.

The Montgomery County Sheriff's Office is asking anyone with information or who has seen the car to contact them at 540-382-4343.

Capt. Brian Wright of the sheriff's office said in an email to USA TODAY on Tuesday morning that deputies are actively working and following up on leads but declined to comment further.