CHICAGO - The fatal shootings at an Oregon community college on Thursday (Oct 1) were the latest of many deadly rampages in the United States.

Below are the five worst shooting incidents in recent years, ranked by the number of dead, including the shooter.

1. April 16, 2007

Virginia Tech: A gunman slaughtered 32 people and shoots himself at a university in Blacksburg, Virginia. The massacre was the deadliest one by a single gunman in US history.

The shooter, Seung-Hui Cho, was a 23-year-old undergraduate at the time of the massacre. He had locked the doors of a classroom building at Virginia Tech from the inside and fired 174 rounds in nine minutes, gunning down 30 people and then killing himself. Earlier, he had shot dead two others in a dormitory across the campus. The entire shooting rampage went on for two hours.

Cho was described as a sullen loner and was said to be mentally disturbed. In a suicide video which he mailed to NBC news, he incoherently absolved himself and blamed society for the massacre. "You had a hundred billion chances and ways to have avoided today," he said in one. "But... you forced me into a corner and gave me only one option. The decision was yours."

Virginia Tech implemented new alert systems, including text alerts to students' phones to inform them of incidents on campus, after facing criticism that the school had not reacted swiftly enough.

2. Dec 14, 2012

Sandy Hook: Gunman Adam Lanza killed 20 children and six adults and himself at Sandy Hook Elementary School in Newtown, Connecticut.

Lanza, who was 20 at the time, killed his mother Nancy, 52, while she was in bed before heading to Sandy Hook Elementary School, where he was once a student.

He had been armed with 30 rounds of ammunition, a Bushmaster .223-caliber semi-automatic rifle, a Glock pistol and a Savage Mark II rifle. The guns were legal and owned by Nancy who was a gun enthusiast and advocate.

Although the school had implemented safety measures such as locked doors which meant visitors had to be buzzed in, Lanza used his assault weapon to shoot his way into the school.

After killing people, Lanza turned the gun on himself. The loner in school was diagnosed with Asperger's syndrome and displayed obsessive compulsive traits, including washing his hands and changing his socks multiple times in a day. He was also said to be obsessed with mass murders.

3. April 20, 1999

Columbine: Two heavily armed teenagers went on a rampage at Columbine High School in Littleton, Colorado, shooting 12 students and a teacher and wounding more than 20 others before taking their own lives.

Students Dylan Klebold, 17, and Eric Harris, 18, were friends who bonded over a plan to attack the school. Harris was the smart one who could be charming if he wanted to, later characterised as the psychopath, while Klebold was the anxious depressive who was also paranoid.

On the morning of April 20, the duo brought home-made bombs and guns to the high school in Colorado. The bombs fizzled as they were badly made, but the boys were armed a pistol, a rifle and two sawed-off shotguns which they used to kill 13 and wound 24.

They then turned the guns on themselves.

The shocking high school shooting kickstarted the first wave of self-reflection in America about everything from high school bullying to gun control laws.

4. April 3, 2009

Immigration centre: A Vietnamese immigrant opened fire at an immigrant services centre in Binghamton, New York, killing 13 people and wounding four. He then kills himself.

Police said the 41-year-old Jiverly Wong was apparently upset about losing his job and being picked on for his limited English.

5. Nov 5, 2009

Fort Hood: A gunman opened fire at Fort Hood, a US Army base in Texas, killing 13 people and wounding 32.

US Army major and psychiatrist Nidal Hasan was sentenced to death for the rampage.

Hasan had opened fire at a medical facility on the Fort Hood base, a staging point where soldiers are deployed to combat zones. Twelve of the dead and 30 of the wounded were soldiers. Hasan was shot by a civilian police officer who responded to the attack.

During his trial, it was learned that Hasan was a US-born Muslim of Palestinian descent who opposed the American military occupations of Iraq and Afghanistan.

He had also spoken online with radical cleric Anwar al-Awlaki, a US citizen later killed in an American drone strike in Yemen. He had carried out the shooting as part of an effort to become a martyr.

SOURCE: REUTERS, ST ARCHIVES, CNN, NBC