Traffic was at a standstill for miles on Interstate 76 Thursday when an accident involving a horse trailer claimed the life of one man, his dog and three horses.

The State Highway Patrol has identified the man who died as thirty-one-year-old William Tankard of Aiken, South Carolina.

A preliminary investigation revealed that around 3:45 p.m., a semi-tractor trailer was slowing in traffic eastbound on I-76 in the right lane.  A passenger car was slowing in traffic behind the semi. 

An F-350 pick-up truck hauling a trailer with thoroughbred horses was eastbound behind the passenger car changing lanes attempting to pass in the left lane.

While making the lane change, the pick-up struck the passenger car, rolled on its side, struck the bridge, continued east and struck the back of the semi.  The driver of the F-350 was pronounced dead at the scene along with his dog that was in the passenger compartment of the pick-up with him. 

Troopers say ten horses were inside the trailer that tipped over. Three horses died. The other seven survived but, were injured.

Witnesses and bystanders jumped into action to assist.

"I jumped out and grabbed the horse that was running, the police were trying to catch before," said Jerome Wyckoff of Alliance.

Those on scene tried to corral the horses and keep them calm. Some had experience with the animals, other had no experience.

"We found some of the stuff on the road bandages, antibiotics and we're patching them up as best as we could," said Dave Lescsak of Austintown.

The surviving animals were loaded into trailers and taken to Campbell's Stone Creek Farm and Vernon's Farm in Milton Township, where they were examined by a veterinarian.

"There are some extensive injuries, right now non-life threatening. The biggest concern in the future is infection," said Dr. Steve Miletta with Lisbon Veterinary Clinic.

Dr. Miletta spent hours tending to the animals. He said they are resilient and will likely overcome the trauma of the accident.

"They did a tremendous job. The fire department, the E.M.T's and everyone involved," said Miletta. "Most of these wounds were pretty clean. They had antiseptic on them already. They tried to bandage them the best they could."

The eastbound lanes of Interstate 76 over Lake Milton were completely shut down for nearly four hours due to the traffic accident. Traffic had to be detoured along Mahoning Avenue.

It's still not clear what exactly caused the accident. The State Highway Patrol had a reconstruction team on scene and is investigating.

Others involved in the accident have been identified as:

Driver of Semi: Nicorf Girard, 43 years old, Montreal Canada

Driver of Saturn: Edmund Gates 67, years old, Cleveland, Ohio

Passenger of Saturn: Karen Gates 66, years old, Cleveland, Ohio

Lt. Nakia Hendrix of the Highway patrol says that so far this year there have been 10 crashes with 11 fatalities in Mahoning County.  5 of those crashes have been in rural areas with 6 killed and 5 urban crashes with 5 killed.