By Ashli Sims, The News On 6

TULSA, OK -- The death of a crooked neck giraffe at the Tulsa Zoo in early December continues to cast a dark cloud over what was once voted America's favorite zoo.

A city of Tulsa internal audit report reveals the trailer that brought Amali to Tulsa had bloody marks on its ceiling. The 47-page audit chronicles what led up to the 5-year-old giraffe's death, and for the first time, a Tulsa Zoo curator admits a mistake was made.

Tulsa Zoo officials say no one is more broken-hearted over the death of five-year-old Amali than they are.

Staunchly defending their actions and efforts to save Amali, the Tulsa Zoo has never really admitted any mistakes until now.

The mayor called on Tulsa's auditor to look into what happened to Amali. He produced a 47-page report, including more than 200 photographs and a dozen interviews with witnesses.

The report reviews the purchase of Amali from an Ohio zoo and the hiring of the company that specialized in transporting giraffes.

According to the report, eight witnesses said they heard the transport driver say Amali "didn't settle down, ride well or travel well during the trip."

In these pictures obtained by the News on 6, you can see Amali's horns are bloodied. The report says there were "blood marks in the trailer" and the "top of the trailer was bloody."

But it also says "abrasions and blood marks were not considered unusual" and might not have anything to do with Amali's neck injury.

As first reported last month, sales records obtained by the News on 6 show that Tulsa Zoo officials thought Amali "arrived in good shape."

The large animal curator who made that statement is now calling the comment an "error."

She says in a letter included in the auditor's report that she noticed a bulge in Amali's neck but "her overall condition was good otherwise," and the giraffe showed "no signs of discomfort, stress, or mobility problems."

The curator goes on to say she based her assessment more on the animal's actions than her medical condition. And she should have said the "animal was in 'fair' or 'poor' condition."

We still have not heard anything from the transport driver. The audit says an interview with the driver is pending.

The Tulsa Zoo is also still waiting on a report from the U.S. Department of Agriculture.