An increase in Minnesota fire deaths the first half of this year has firefighters concerned.

Fire deaths rose 36 percent in Minnesota during the first 6 months of 2017, according to State Fire Marshal Bruce West. There have been 30 deaths so far this year, outpacing the average from the first half of the previous five years, 26.8 deaths.

Though the preliminary data doesn’t show a leading cause, West said most fatal fires are caused by human behavior.

“We just want people to be aware of what they’re doing, to be aware of the increase, and to show a little extra care,” West said.

Typically, careless smoking causes the most fatal fires in Minnesota. While smoking this year so far has only been identified as the cause of one fatal fire, most of the cases remain under investigation. Other causes include an unattended portable heater, cooking grease, suicide and careless open burning. Three of the fires - 10 percent - were from gas leaks.

“There’s no real trend (in the overall numbers),” West said. “We see peaks and valleys. One year we have a reduction, the next year we might have a peak. Careless smoking continues to be the number one cause overall.”