Her name was Sambo β€” and after a life of hard labor, she's gone.

She'd been carrying two tourists through the scorching heat in Cambodia for 40 minutes when her body couldn't take it anymore. Just after last week's collapse at Angor Elephant Park, where she's worked for the past 15 years, 45-year-old Sambo died of a heart attack.

People stood by her body and cried, according to The Independent. Temperatures that day reached 104 degrees Fahrenheit.

Sambo is sadly not alone in her plight. Elephants who are forced to give rides often collapse out of sheer exhaustion.

What happens before an elephant ride is enough suffering for a whole lifetime. After the "training," which crushes the animal's wild spirit, the elephant is used for profit at tourist attractions. Then, what happens to elephants' bodies when people ride them just adds to their pain.

A tour operator told AFP that work hours for the park's remaining elephants would be reduced. But people around the world are calling for more drastic measures to be taken in the wake of Sambo's death.

"There is no such thing as cruelty-free elephant rides," a new petition, in memory of Sambo, states. "Tourists may think that riding an elephant on holiday does not cause harm β€” you often can't see the cruelty β€” it's hidden from view."

For Sambo, only the sad end of her life was out in the open for everyone to see.

Thirteen elephants remain at Angor Elephant Park β€” and their lives hang in the balance.

Click here to tell APSARA (Authority for the Protection and Management of Angkor and the Region of Siem Reap) to ban elephant riding at Angkor.

Read about a campaign urging TripAdvisor to help tourists make more informed decisions here.

The video below shows the elephant rides in Angkor.