DENVER (AP) — A total of five people have died in crashes on a Colorado interstate involving over 30 vehicles, including seven semitrailers, after blowing dirt made it nearly impossible to see, authorities said Wednesday.

Authorities initially said four people died and 29 people were injured in the crashes Tuesday on Interstate 25 near Pueblo. But one of the people hospitalized later died of his injuries, the Colorado State Patrol said.

Dirt from parched land along the interstate was kicked up by heavy winds and blew across the interstate around 10 a.m. Tuesday causing a “brown out,” Maj. Brian Lyons of the Colorado State Patrol said.

“Visibility was next to nothing,” he said.

There were gusts of up to around 70 mph (113 kph) reported in the region Tuesday morning, according to the National Weather Service. Video from one driver stuck in traffic show waves of dirt billowing across the interstate and the wreckage becoming visible through the dusty haze.

The injured were taken to hospitals with injuries ranging from minor to severe, Lyons said. There were crashes on either side of the interstate, but the one on the southbound side only led to property damage, the patrol said.

One of the vehicles was a pickup hauling a livestock trailer, which was carrying 30 sheep and one goat, according to the Humane Society of the Pikes Peak Region, which was called to help. Some of the animals were trapped in the damaged trailer while others ran loose until its staffers were able to catch them, the humane society said. Four of the sheep, which were initially described as goats by authorities, were too severely injured to recover, the humane society said.

The cause of the crashes about 2 miles (3.2 kilometers) from Pueblo is still being investigated. The lack of visibility will be considered as one of the factors, but others may also be involved, said Trooper Sherri Mendez, a patrol spokesperson.

The strong winds that hit the eastern half of Colorado on Tuesday, combined with warm weather and very dry conditions, were also blamed for fanning wildfires and causing flight delays at Denver’s airport. More strong winds and dry conditions have elevated the fire danger there again on Wednesday.