Three men died at Michigan country music festival Faster Horses this weekend, from what police suspect was carbon monoxide poisoning.

Lenawee County Sheriff’s office confirmed a group of five men in their early 20s were found unresponsive in their travel trailer on Saturday afternoon (July 17) – three having already passed at the scene.

The remaining two people were taken to emergency care and placed in critical condition, where they are being treated for the suspected ailment.

In a statement released by the sheriff's office, they said the events and deaths surrounding them are investigated as "a suspected carbon monoxide exposure from a generator located very near the travel trailer.

First responders stress the importance of keeping generators away from camping areas, tents, travel trailers etc., as well as exhaust fumes from running vehicles," they added.

In what appears to be an unrelated incident, local police are also investigating the death of a woman on the grounds of Faster Horses, who passed away early Saturday morning.

The authorities have released no suspected cause of death. However, they are appealing for information regarding an individual seen with the deceased before her death.

UPDATE: The deceased female has been identified as Melissa Donna Havens. The investigation continues into the cause of death of Havens. An autopsy will be performed along with toxicology test. Detectives need assistance with information or tips helping them pic.twitter.com/22OUFHgKwf

— MSP First District (@MSPFirstDist) July 17, 2021