WESTMINSTER, Texas -- The names of the four people killed and nine injured in a horrific crash Tuesday on State Highway 121 in Collin County have been released.

Abigail Kendall, 15, Brianna Gesino, 15, Julie Trimble, 51, and Wayne Trimble, 51, died at the scene, DPS said. Nine people were sent to the hospital with varying injuries. All of those injured were sent either to Medical City McKinney or Medical City Plano.

Authorities confirmed five vehicles were involved in the crash at State Highway 121 near County Road 528, just outside of Anna. Troopers were called to the scene shortly after 4 p.m.

An initial investigation indicates a Pontiac Grand Prix, which four teens were in, was driving northbound on Highway 121 when it slowed down for an "undetermined reason," officials say, and set off a series of spin-outs and head-on collisions.

The Pontiac was first rear-ended by a Dodge pickup, causing the Pontiac to spin into oncoming traffic and hit a Ford Focus traveling in the other direction. The Ford Focus then spun into oncoming traffic and was struck by a Ford F-450 utility truck. A Subaru heading southbound was also struck by the Pontiac and rolled into a ditch.

Two of the teens in the Pontiac, Zoe Wilson, 16, and Madison Kenney, 16, were injured and taken to Medical Center McKinney. Anna ISD said Kendall, 15, was a student and Gesino, 15, was a former student at Anna High School.

A fund has been set up to help with funeral expenses for Gesino, according to this Facebook post.

"The Anna ISD family extends our deepest sympathies to the family and friends of these students. We are praying for all the victims and their families in this accident and for a full recovery for the others involved," the district said on Facebook.

The Trimbles, from Ivanhoe, Texas, were in the Ford Focus and died at the scene. The other two people in the vehicle, Heather Trimble, 24, and her 4-year-old daughter, were rushed to Medical Center Plano with serious injuries.

A GoFundMe page set up for Heather revealed that she was eight months pregnant at the time of the crash, and doctors delivered her baby girl early. The baby and Heather are said to be on breathing machines, while her 4-year-old daughter had bruises and is said to be doing well.

Heather Trimble and daughter (GoFundMe)
The Trimble family (GoFundMe)

The three people in the Dodge pickup, Anne Spann, 45, Christopher Spann, 42, and Christopher Spann, Jr., 14, of Bailey, Texas, were taken to Medical Center McKinney with non-life-threatening injuries.

The driver of the Ford utility truck, 62-year-old Billy Vanhoose of Rowlett, sustained serious injuries and was taken by air ambulance to Medical Center Plano. The driver of the Subaru, 17-year-old Emrie Morris of Allen, was seriously injured and taken to Medical City McKinney.