The search continued Monday night for a missing Somerset County man who hasn't been seen since Sunday afternoon.

Crews took to Laurel Mountain for nearly 12 hours Monday.

Family and friends are worried not only because of changing weather conditions and terrain, but also because of the medical illness Bruce Maust suffers from. 

State police, three fire departments along with Westmoreland County rough terrain rescue crews were all a part of the search.

"You just think the next call they're going to say, we found him somewhere," Timothy Maust said.

Timothy was feeling overwhelmed as he became part of the manpower searching for his missing brother. 

"He went out by himself on his snowmobile and nobody's seen him since," Timothy said. 

"[He] left from his mother's house and his destination was another brother's house," Corporal Stephen Adamczyk said.

Bruce Maust was last seen about 3 p.m. Sunday. 

"[My] worst fear is someone being out that may have some physical problems, and obviously no water or food or anything," Jennerstown Fire Chief Dave Robertson said. 

Crews are not only fearing for his safety, but Maust also suffers from Pick's Disease. 

According to Bruce's brother, dementia is a major symptom of the disease.

"He has the right equipment but with his disease, it's a possibility he made a left instead of a right," Adamczyk said.

"Locally, there's people doing searches around here. Now, we're at a standstill because we don't know where else to look as far as areas that he may have gone," Timothy said.

His brother said Bruce is an experienced snowmobiler and familiar with the trails.

He left wearing a red, black and grey Polaris suit.

His snowmobile is a Polaris XC.

"It's amazing what people will do to help others people and I'm just really grateful for all that," Timothy said.

Teams of search crews from Jennerstown, Friedens and Bakersville canvased Somerset County in hopes of finding Bruce.

With weather and darkness setting in, the search continued into its 12th hour Monday night. 

"We're talking some big ravines, big rocks, a lot of water hazards that everyones going to have to be careful," Robertson said.

"We're going to continue our grid search until we're sure that we've done an effective search of this area and that he's not in it," Adamczyk said.

Crews were expected to wrap up Monday night's search around 11 p.m.

Volunteers are scheduled to search by ground and air again Tuesday at 8 a.m.