Mayor Dave Bing says Detroit had 93 fires during the traditional arson period around Halloween, compared with 94 the previous year.
Bing told reporters Thursday that the hundreds of volunteers who participated in Detroit's "Angels' Night" patrols put on a "tremendous" effort. The stepped-up fire prevention efforts run for the three days that end on Halloween.
The Angels' Night program is a long-running response to what used to be known as Devil's Night, the day before Halloween that once saw large numbers of arsons in Detroit.
In 1984, the city had more than 800 fires during the period.
This year's fires included 39 in occupied dwellings, 20 in vacant buildings, 12 in vehicles and 18 in rubbish. Fire Commissioner Donald Austin says 39 of the 59 structure fires are suspicious.