Oregon College Gunman's Motive An Open Question

A neighbor of the man who went on a deadly shooting rampage at an Oregon college, killing 10 people, including the shooter, said he "seemed really unfriendly."

Umpqua Community College is now a crime scene and will remain closed until Monday after a gunman opened fire Thursday, killing nine people and critically wounding seven others.

Authorities have yet to determine Chris Harper Mercer's motive. He also died in the gunfire, reports CBS News correspondent John Blackstone.

The first sign of trouble on the small campus of some 3,000 students, about 180 miles south of Portland, in Douglas County, was around 10:40 a.m. Minutes later, the scope of the shooter's rampage climbed to a possibility of at least 20 victims. 

One student said her teacher heard loud noises in the classroom next door. 

"She said, 'Hey, is everyone OK over there?' And then as soon as she said that, multiple shots were fired. And when she turned and she looked at the classroom, the look on her face was horrifying, and that's when I knew something was wrong," the student said. "When she looked at us, she said, 'We have to get out - now."'

Law enforcement quickly arrived at the scene. Just 12 minutes after the initial 911 call, the suspected gunman was dead. 

"We do know that we have at least two heroic officers who responded into the building within minutes and exchanged gunfire with the suspect," said Douglas County Sheriff John Hanlin. 

Hundreds of people attended a candlelight vigil in Roseburg late Thursday. 

"It's amazing, the turnout. But this is our community, this is who we are. ... [We are] not what happened today," said former Umpqua Community College student Jennifer McMaster.

At this point, it is still unclear if the gunman was shot by police or took his own life.  What is clear is the devastating impact his actions have had on this tightly-knit community.

Oregon's governor has ordered that flags at all state buildings be flown at half-staff until sunset Friday.