In less than 24 hours, more than $30,000 has been raised for a reward in an effort to find out what happened to a University of Alabama student who went missing Sunday morning.

A GoFundMe account has been started by Garrett’s brother Mitchell Walker. In 21 hours, the site raised $31,104 from more than 500 donors. 

On Tuesday, rescuers continued searching the Black Warrior River for Garrett Walker, a 20-year-old junior from Maryland, who was last seen at a downtown Tuscaloosa bar and was reported missing Sunday afternoon by his parents after his mobile phone was located near the Tuscaloosa Riverwalk

“He is a white male, 5’8 and 160 pounds. He was last seen near the Gray Lady bar in Tuscaloosa, and then the river walk area,” the post on GoFundMe said. “Please donate towards a reward for information/whereabouts of Garrett. His family just wants to see him come home safely.”

Tuscaloosa Fire Rescue and Tuscaloosa Police Department crews began searching the river at first light on Monday.

The search continued through Tueday.

During the investigation, Tuscaloosa police officers recovered articles of clothing believed to belong to Walker both in and near the Black Warrior River, about a half a mile from the bar where he was last seen, near the former dock of the Bama Belle, officials said.

Officials from the Tuscaloosa Police Department said they believe Walker is “in the Black Warrior River” and that divers will continue to search the river to try to locate him.

Search crews are using three boats to search the river, first responders are also using drones to see if any more evidence can be seen from the air.