$20K reward offered for student who vanished at Michigan State University

Its been 81 days since the teen went missing vanished No leads from authorities, FBI Reward increased to 20K and growing Social media search growing

It's been nearly three months since 18-year-old Brendan Santo vanished while visiting friends in East Lansing, Michigan, the weekend of the Michigan-Michigan State football game.

There have been no clues yet as to what happened to the Grand Valley University student who disappeared on Halloween weekend, but the search for him continues, and his family is not giving up hope. "We just want Brendan back," they told ABC News.

"It is unfathomable to believe in this day and age someone can just disappear," Brendan's aunt, Dawn Brewer, said. "Our family is desperately begging anyone with information to come forward even anonymously."

Santo was last seen around midnight on Oct. 29 on MSU's campus, near Yakeley Hall, authorities said. He was wearing grey sweatpants, a black T-shirt, a Detroit Red Wings cap and Converse high tops, police said. He's about 5-foot-10 and 160 pounds.