SEDALIA, Colo. (CBS4) – Douglas County authorities responded to the 7000 block of Rainbow Creek Road Sunday afternoon following a fatal lightning strike southwest of Sedalia.

(credit: CBS)

(credit: CBS)

A Douglas County Sheriff’s Office spokesperson confirms a 36-year-old woman and one horse were killed. A 15-year-old girl was injured and was taken by ambulance to Sky Ridge Medical Center. The teenager was listed in serious condition, according to Deputy Jason Blanchard.

Both were riding the horse at the time, Blanchard said.

( credit – CBS4)

According to the National Oceanic and Atmospheric Administration, the death was the first caused by lightning in the U.S. this year.

A fast-moving thunderstorm, presumably the same one that unleashed the lethal lightning strike, ran south to north across the metro area beginning at 3:30 p.m.

In Denver, it caused a tree to snap and fall onto the roof of a house east of City Park. The Denver Fire Department said nobody was home when the tree fell on the home.

( credit – Louis Ruiz)

(credit: CBS)

Tree limbs and power lines suffered in Aurora.

Saturday evening, a woman watching a Little League game in Highlands Ranch was also struck by lightning.

The department later said the woman’s injuries appeared “non-life threatening.”

Colorado is consistently one of the leading states in the U.S. in lightning strike deaths. Consult CBS4’s Hiking & Outdoor Weather Resource page for the latest conditions before heading outside during storm season.