SAN FRANCISCO (CBS SF) — The family of a San Francisco college student is growing more concerned over his nearly week-long disappearance. Chris Liang told his family he was making a sudden trip from San Francisco to Southern California on Monday, February 28th. He hasn’t been heard from since.

Liang’s older brother Jerry said he’s feeling numb and shocked.

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He said Chris shared a photo of himself in his newly rented Tesla before he told his family he was headed to Irvine. Monday was the last day Jerry said Chris was in contact with anyone.

“I’m trying to prevent myself from going to think about too many ‘what ifs’ like maybe I should have posted on social media earlier, what if my brother’s out there incapacitated,” said Jerry Liang.

Jerry said his younger brother texted him at 1:40 am on Monday and described his plans.

“(He was going) to meet with a friend to do something that really wasn’t within his boundaries to do for this friend. I’m not going into too many details, I don’t want to call him out on national television in case he comes back alive and gets too embarrassed about it, but there was also really erratic choices,” said Jerry.

Jerry said he became even more concerned because Chris struggles with mental health issues. He said the Tesla app showed his last location to be in the Central California town of Firebaugh, where there is a supercharging station.

“The entire premise of this trip was pretty insane,” Jerry said. “He got his driver’s license last March. He’s never driven since. He’s never driven from NorCal all the way to SoCal. He’s never booked a hotel on his own, and the premise – him just renting this Tesla, during the school week, he’s still in school right, and to do all these crazy things he’s been telling us about was just very concerning.”

Jerry grew more concerned when Chris’ friend said he never made it to Irvine. His phone is inaccessible. He didn’t return his rental car on Wednesday and missed his classes.

He is a senior at the University of San Francisco studying business.

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USF said in a statement to KPIX 5:

“USF staff has been working with the family of our student Christopher Liang. If you have information that can help locate Chris, please call USF Public Safety dispatch at (415) 422-4201.”

The San Francisco Police Department said:

“We are aware of this missing person report and that this person is currently missing. The report was made with Irvine Police Department. Please contact Irvine for any further details/statement. I’m not sure what you mean that SFPD has not declared him missing.”

After taking to social media and pleading with others to use the hashtag #findchrisliang, Jerry organized a search party and drove down to the Central Valley looking for any sign of Chris on Saturday.

He said Chris had complained to one of his friends that his Tesla was malfunctioning for about 20 minutes. Its location is not accessible via an app.

“He could be anywhere between San Francisco and Irvine, so local police departments, because they don’t know where he was missing out of – no one sort of really took on…. ownership of finding him,” said Jerry.

He also added that police investigators told him that the circumstances, however strange, aren’t enough to prove that foul play is involved, nor do they allow police to request a search warrant.

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He has created findchrisliang.com and the family is offering a $25,000 reward for a tip leading to his whereabouts.

Source: sanfrancisco.cbslocal.com.