WASHINGTON, Mo. (NewsNation Now) — A tractor trailer carrying 29 horses flipped on I-44 in Missouri last night. Thirteen of the horses died or had to be euthanized.

It happened just west of the Washington exit around 8:15 p.m. Sunday in Franklin County. The Boles Fire Department, Missouri Highway Patrol, the MERS Large Animal Rescue, Homestead Veterinary Services and the Missouri Humane Society were called out to assist with the rescue.

The Missouri Highway Patrol is still working on its crash report but it appears the tractor-trailer flipped into the median.

Bill Schmidt with MERS Large Animal Rescue tells NewsNation affiliate KTVI his crew of nine were on the scene until 3:15 a.m.

The horses were removed with help from pull ropes from the fire department. Every horse needed a halter to be removed from the vehicle.

Schmidt says shortly after the accident, three horses escaped and were eventually found by the Highway Patrol west of the exit on HWY 100.

MERS Large Animal Rescue posted on Facebook that the Humane Society of Missouri Investigator and Veterinarian evaluated and transported the loose horses.

The crews created two areas or pens, one to contain animals as they were loaded off the back of the trailer, and the other for triage.

The 16 surviving horses were taken nearby to the Humane Society’s Longmeadow Ranch in Union. There is no word on if any of them are injured.

NewsNation affiliate KTVI contributed to this report