SAN MARCOS (CBS 8) - Someone called 911 after they thought they saw a man holding a riffle at Cal State San Marcos. That triggered a campus-wide lock down that lasted 40 minutes.

After the call came in, before 9:00 a.m. Wednesday, sheriff's deputies and campus police swarmed the grounds. They were searching for a suspect described as a bald white man, wearing a black shirt and jeans.

When they swept the area and confronted the man, they checked his car and he was found unarmed and carrying an umbrella and umbrella case.

Meantime, officials had a "shelter in place" order.

The bald man was Julius Williams' coworker who works for campus IT. Williams says there is an elaborate warning system in place for emergencies and natural disasters. Hundreds of staff and students were notified by text, email and phone. They even received play-by-play updates of the situation.

"First it was a lockdown, then there's a man on campus. Then they're headed to the Science Hall 302. It's a step-by-step process and then it alerts us to stay inside," Williams said.

Margaret Chantung, with Cal State San Marcos, said: "Campus police immediately sprang into action to ensure the safety of our university."

The lockdown was lifted at 9:40 a.m. Officials says even in this case it's better to be safe than sorry.