One person is dead and three others are in critical condition after a suspected drug overdose at a party in Anaheim early Sunday morning, police said.

Police and emergency personnel responded to reports of people lying unconscious outside an apartment building in the 1500 block of Benmore Lane at 1:09 a.m., Sergeant John Johnson said. Ta. Armando Pardo of the Anaheim Police Department.

First responders found four men in a grassy area in front of the building and a white powdery substance nearby. Paramedics and police officers suspected a drug overdose and began a rescue operation.

“It’s not normal for four people to be unconscious at once,” Pardo said.

The four men were transported to area hospitals. One person has since died and three others remain in critical condition, Pardo said. Their ages were unknown.

A hazardous materials worker arrives to collect the white powder and is currently examining it. Officers cordoned off the area for three hours. Pardo said about 30 people were at the party when police arrived. A subdivision of the ministry is investigating, but no arrests have been made.