On Monday, five people were killed in less than six hours on the streets of St. Louis. Seen from a gated suburban community or a small country town, that may reinforce a view that the city is no place for decent folks.

Seen from the front porch of one of the city’s growing expanse of stable neighborhoods, five killings in six hours is an aberration, a freakish coincidence. Crime is down drastically in the city, particularly crimes against persons — murder, rape, assault and robbery.

Homicides are up this year. But five in six hours? In broad daylight? Hardened city cops see Monday’s killings as crimes of exceptional callousness, committed under conditions a community should not ignore.

The crimes:

• During the lunch hour that day — 12:30 p.m., according to the police report — three men walked into a discount store in Old North St. Louis. They demanded money. They blasted away at a man and a woman occupying an office behind the front counter, killing both. They shot a woman seated at the counter helping a customer. She was five months pregnant. She survived.

• Fifteen minutes later, on Gano Street in the Fairgrounds neighborhood three miles to the north, three men were standing in front of a house talking. One walked into the gangway beside the vacant house next door, where he was shot in the back and under his left armpit. He collapsed in the front yard and died. The shooter stepped out of the gangway and fired several shots at the other two men, striking one in the head, killing him.

• The fifth killing occurred three blocks away, on North Grand Boulevard, at 7:11 p.m. Two men approached the victim on the street. They began firing. The victim ran into a store and collapsed in an aisle, bleeding from his face and a puncture wound to his upper chest. He was lifeless when paramedics arrived.

Most murder victims are killed by people they know, in domestic disputes or arguments over money or drugs. Stranger-on-stranger killings, as apparently occurred at the Rock Bottom Wholesale store in Old North St. Louis, are rarer.

Old North St. Louis is a neighborhood on the move — a beehive of activity that in recent years has become a model of community involvement. Rough blocks are being smoothed out with new and renovated housing. What happened on May 12 had to be a sickening blow.

The Fairgrounds neighborhood is a different story. Although the vast majority of its people are honest and law abiding, this area is held hostage by a small group of dangerous young men. Gangs and guns are a fact of life.

The St. Louis Police Department made arrests in about 55 percent of the city’s homicides in the last three years. Police already have two suspects under arrest for the Old North St. Louis killings. The department is beginning a major initiative to reduce gun violence, a broad partnership under the guidance of the Police Executive Research Forum, a national law enforcement think tank. The focus will be on the Wells-Goodfellow neighborhood in the northwest corner of the city, the site of 14 homicides in 2007.

Five killings in six hours do not mean that the city has become frighteningly dangerous, but they can’t be shrugged off, either. Rooting out the violence and the conditions that foster violence will require a commitment from the entire community: Relying on police and prosecutors to put bad guys away will be futile if we fail to create schools that work, provide housing that is safe and infuse all children with hope.

(Photo: Laurie Skrivan, Post-Dispatch. Medics work on one of the victims of the Gano Street shooting.)