Pennsylvania State Police are investigating a deadly Amish buggy accident in Pennsylvania that occurred late Saturday afternoon. The collision between the buggy and a truck, which happened around 4:20 p.m., left two people dead and a third critically injured.

The buggy was traveling along Pulaski Mercer Road in Mercer County, roughly 60 miles northwest of Pittsburgh, when a semi-truck rear-ended the horse-drawn buggy. According to The Associated Press, the truck was driven by 36-year-old Matthew Coulter.

An Amish woman, identified as 34-year-old Mary Byler, and her 11-year-old daughter were killed in the buggy accident. According to Web Pro News, the two were pronounced dead at the scene. Both died of blunt force trauma.

The driver of the horse-drawn buggy, 35-year-old William Byler, who was the husband of the woman who was killed in the collision, was flown to a hospital in Youngstown, Ohio. He is in critical condition.

The horse that was pulling the buggy was also seriously injured. Authorities were forced to euthanize the animal because of the severity of the animal’s wounds, according to Web Pro News.

Authorities are in the middle of investigating the deadly Amish buggy accident. It’s unclear whether the truck driver, who dialed 911 after he rammed into the back of the buggy, will face charges.

Only a few days prior to Saturday’s deadly Amish buggy accident, on Thanksgiving, another collision involving an Amish buggy occurred in Wisconsin. According to WAOW, one man was arrested on suspicion of drunk driving after he plowed into a horse-drawn buggy traveling down County Highway G in the town of Grant, injuring two of the buggy’s occupants. They were taken to a hospital where they were treated for non-life-threatening injuries.

Amish buggies typically travel along the shoulders of highways and have orange, reflective “slow moving vehicle” triangles attached to their rears. Still, accidents, especially between buggies and automobiles, do occur, and can be fatal. According to the Ohio Department of Transportation, the state, which has a large Amish population, has an average of 120 buggy accidents a year.

Amish buggies travel between 5 and 8 mph. “Imagine traveling at 55 mph and coming upon a car traveling at 45 mph that is 500 feet ahead,” the department of transportation posits on its website. “After six seconds, you will have 412 feet to react before colliding with that car. However, if traveling at 55 mph and coming upon a horse-drawn vehicle traveling a 5 mph that is 500 feet ahead, you will have only 44 feet to react before colliding in the same six seconds.”