Something very strange happened here this week: the city which is known perhaps as much for its crime as for its cars went six days without a reported homicide.

It has been almost a decade since something like that happened here, and nobody seemed to understand quite why it happened this time.

"It's 'cause we're taking care of business, man," joked Alex Luvall, a young assistant to William Hart, the city's first black police chief and the man who took over the department last fall after great internal ltrife in the department and a summer marked by violent youth crime.

But neither Hart nor his top deputy, Executive Deputy Chief James Bannon, could offer any clear-cut explanation for the dropoff in killings.

Bannon, 48, a police veteran with a PhD in sociology, was out strolling around downtown today just after the homicide unit was called to the killing that broke the six-day string.

"It's like some guy stepping up to a dice table and shooting off Alx Luvall, a young assistant to William Hart, the city's first black police chief and the man who took over the department last fall after great internal strife in the department and a summer marked by violent youth crime.

But neither Hart nor his top deputy, Executive Deputy Chief James Bannon, could offer any clear-cut explanation for the dropoff in killings.

Bannon, 48, a police veteran with a PhD in socioloy, was out strolling around downtown today just after the homicide unit was called to the killing that broke the six-day string.

"It's like some guy stepping up to a dice table and shooting off a string of sevens without crapping out," Bannon said. "All we can do is be grateful."

He said he believes improved police work has reduced the number of execution and felony murders in the city, but he nioted that the police could hardly take credit for the lack of family homicides during the period.

He pointed out, moreover, that while there more than two dozen shootings.

"That means there was all the motivation, all the behavior required for a homicide," he said. "It's just that the results weren't that disastrous."

Not all of the shootings in Detroit this week seemed intentionally directed foward homicide, however.

On Sunday, a 10-year-old girl was wounded after she rolled over on top of the .22 cal. rifle she was sleeping with.

On Monday, a Detroit police officer was hit by his own bullet after he shot a dog that was attacking him and the bullet shattered. The same day, a 21-year-old Detroiter shot himself in the foot while trying to execute the neighbor's cat he was holding between his knees.

Other shootings occured during armed robberies and other crimes, of course. But for reasons of a few inches here and there, no one died.

The man who broke the string was identified by police today was Homer Hill, who they said managed an apartment building on the city's near West Side.

Neighbors said he had been having trouble collecting rent and that he carried two guns, one a long pistol and the other a small gun which he kept in his boot. They theorized that the slaying must have baen an ambush.

Both Hart and Bannon pointed out today that crime in general has been steadily decreasing in the city since last fall.

A report to the civilian Board of Police Commissioners this week showed that the homicide rate had dropped 26.5 per cent since October, armed robbery was down 23.7 per cent and rape was down 12.7 per cent.

There have been 95 homicides in Detroit so far in 1977 as of this afternoon, compared with 122 at the same date last year, 104 in 1975 and 136 in 1974.

The city reached its all-time homicide high in 1974 with 801 slayings, compared with 684 in 1975 and 723 in 1976.

(Washington homicide officers report that the District of Columbia went six days without a homicide as recently as two weeks ago - Feb. 22-28. In recent memory, the record is nine days, Feb. 8-17, 1979).

While acknowledging uncertainty about the exact cause for the pause in homicides, Hart and Bannon suggested a new, more peaceful mood in this city of 1.3 million.

Hart noted a drop in fear of crime, which he characterized as "sometimes just as bad for a city as crime itself."

Describing the murder-free period as "a millon-to-one shot" he said, "We have to give credit to the community. There isn't much we can really do about most homicides. We can do something about felony murders and execution-style killings, but it's up to the people to stop killing each other."

Bannon said he detected more optimism in the city, noting: "I don't think the people feel like we're dealing with the root causes of crime yet, but there is less powerlessness. They've beginning to rise up against the street thugs, and there is no longer that abject feeling of powerlessness."