Tourists flock to Angkor in Cambodia - home to one of the largest operating archaeological sites in the world - to marvel at massive Khmer Empire ruins and ride elephants. For a price, you, too, can sit atop one of these majestic creatures as it carries you around the Angkor Wat temple complex.

Elephant riding has long been the target of criticism from animal activists, who call the practice cruel and harmful. Now, those activists are calling for an end to elephant rides after an elderly female named Sambo collapsed last week after carrying tourists around the historic site.

Sambo, thought to be between 40 and 45 years old, suffered from heart failure after working in extreme heat, Angkor Elephant Company owner Oan Kiri told the Associated Press.

"Veterinarians concluded that the elephant's death was caused by the hot temperatures, which caused stress, shock, high blood pressure and a heart attack," Kiri told Agence France-Presse.

Sambo collapsed on the way to her enclosure after having worked for about 45 minutes, covering a little over a mile of ground, Kiri told AFP.

"The recent death of an elephant, used for tourist rides, at the Angkor temples should be the final wake-up call for the community and tourism industry to take the steps needed to end this horrific practice," reads a Change.org petition that has received more than 30,000 signatures. It asks the Apsara Authority, which is in charge of research, protection and conservation at the Angkor Archaeological Park, to ban elephant rides at Angkor.

"We regret that the beautiful and gentle Sambo has died and we are taking firm action to investigate fully and thoroughly what happened," a spokesman for Apsara Authority told ABC News.

The spokesman cited findings from the Angkor Elephant Company's veterinarian that Sambo died "due to hot weather and high blood pressure which led to choking and heart failure," but added that "the Apsara Authority is doing our own investigation to determine what really caused the death of the elephant."

Temperatures have lately surpassed 100 degrees Fahrenheit, and Kiri told AP that the remaining elephants will work fewer hours following Sambo's death. Eight elephants will now give rides for 2 1/2 hours in the morning and two hours in the afternoon. Five elephants owned by the company are too old to give rides.

Sambo was buried at the complex Friday after working for Kiri's company since 2001, AP reported.

"There is no such thing as cruelty-free elephant rides," reads the Change.org petition. "What you don't realise is that a 'once in a lifetime' or 'bucket list' item for you, means a lifetime of misery for wild animals."

Reports of elephants collapsing and dying after providing tourist rides emerge from time to time in countries such as Thailand and Vietnam.