An apparent fentanyl overdose is being blamed for the deaths of three men who were found in a downtown Los Angeles apartment building Thursday morning.

Police said they received a call at about 1:15 a.m. from the wife of one of the victims asking for a welfare check.

Officers arrived at the building in the 600 block of South Spring Street to find three unresponsive men, a Los Angeles Police Department spokesperson confirmed.

Los Angeles Fire Department personnel and a hazmat team also responded to the apartment, where the three men were pronounced dead.

The unidentified men were described as being in their 40s.

The deaths are being investigated as possible fentanyl overdoses, the spokesperson said.

One officer had to be transported from the scene after suffering from apparent fentanyl exposure.

The officer was responsive and is expected to be OK.

Investigators said the incident appeared to be isolated to a single unit of the apartment building.