Residents of an apartment complex in Anaheim were temporarily evacuated from their homes overnight after a possible overdose led to a hazmat response.

The Anaheim Police Department said it received a call of a possible overdose shortly after 1 a.m. Sunday at a party on the 1500 block of Benmore Lane. There, four men were found unconscious in the yard and were all taken to a hospital, according to police.

One of the men died at the hospital. The conditions of the others are unclear. The identities of the deceased and those who were injured have not been released.

Because a white powder substance was found at the scene, a hazmat team responded to the incident. The investigation prompted authorities to order a temporary evacuation of nearby homes.

After the hazmat team deemed the scene cleared, residents were able to return to their homes.

Police did not say what the powdered substance was.

The investigation is ongoing.