Federal officials say a train driver's failing eyesight was the probable cause of a fiery train crash that killed three people in the Oklahoma Panhandle last year.

Dr. Mary Pat McKay told the National Transportation Safety Board that the driver’s eyesight fluctuated from day to day and he couldn’t always distinguish red, green and yellow lights.

“This was a very bright, sunny clear day,” McKay says. “He may have had difficulty telling which of the lights were illuminated.”

The executive director of the Oklahoma Dept. of Corrections announced Monday he will resign Oct. 1, according to eCapitol’s Shawn Ashley. The announcement from Justin Jones comes after a legislative session where the department’s funding was not increased and its budget practices were called into question by key legislative and executive budget negotiators.

University of Oklahoma officials say a program that puts more course material online is saving students on the cost of textbooks.

OU President David Boren's office says the first year of the Textbook Alternatives Initiatives has saved students about 25 percent off the typical $1,400 yearly cost of textbooks.

OU is trying to push more material online after seeing a study that found up to 70 percent of students were not buying books because of the costs.

The Tulsa Zoo has had to put down a 21-year-old giraffe who had a broken bone in his right, front foot.

Zoo officials said Sunday that Samburu, also known as Sam, died on Saturday. He was born at the zoo in 1992.

The zoo says Sam lived longer than average for a male giraffe cared for by humans. He suffered from osteoarthritis.