Six people died in two crashes on Interstate 25 in Weld County on Monday, including a 3-month-old girl.

The first crash was reported just after 1:30 p.m. at mile marker 243. Four vehicles were involved including a tractor-trailer, according to the Colorado State Patrol.

Five people who were in a 2015 Ford Edge died in that crash — four at the scene and one at a hospital. All five were from Gillette, Wyoming — a 20-year-old man, 20-year-old woman, 47-year-old woman, 51-year-old man and 3-month-old girl, according to the state patrol. 

Gillette is a coal-mining community in northeast Wyoming, about 340 miles north of Denver. 

A number of vehicles were in the left lane of the interstate and slowed down because of traffic in the area, troopers said. 

Investigators believe a Kentworth tractor-trailer driven by a 26-year-old from Denver rear ended the Ford Edge and pushed it into the median, according to a news release.

The tractor-trailer then rear ended a 2013 Ford Focus and pushed it into a 2021 Mitsubishi Outlander before hitting the Ford Edge a second time. The tractor-trailer then collided with the median and came to a stop. 

Investigators do not believe drugs, alcohol or speed played a role in the crash and no charges had been filed as of 1:30 p.m. Tuesday.

At about 2:20 p.m., troopers were sent to a three-vehicle crash about 20 miles south of the first crash.

State patrol said a 2021 Kawasaki motorcycle was headed north in the left lane and changed lanes more than once before hitting two tractor-trailers.

One of the tractor-trailers ran over the motorcyclist, while the other tractor-trailer drove off, according to the state patrol.

The motorcyclist, a 30-year-old from Northglennn, was pronounced dead at the scene.

Investigators said drugs and alcohol were not considered a factor in the crash, but they believe the motorcyclist was driving a high rate of speed. 

The state patrol is asking anyone with information about either crash who hasn’t already spoken with authorities or anyone with dash cam footage of the crashes to call investigators at 970-506-4999 or 303-239-4501.