OKLAHOMA CITY, Ok (KFOR) — An apartment fire affected several residents around two Sunday morning at the Mason Manor apartments near Northwest 23rd and MacArthur. Fire crews said eight apartment units were involved. "We arrived on scene, there was heavy fire in the breezeway between the two apartments behind me," said District Chief, DJ Harris, with the Oklahoma City Fire Department. Apartment fire under investigation in NW Oklahoma City Fire crews said several people evacuated and some even got out through a window. "The occupants on the second floor of the main fire building tried to escape the front door and they realized that the breezeway was completely involved, so they turned around and went out their second-story window on the back side of the apartment," said District Chief Harris. District Chief DJ Harris said they also helped rescue someone from a first-floor apartment and a few animals. Oklahoma City fire crews worked hard to put the flames out quickly. "They were able to work in conjunction and get on the fire from the exterior and then we were able to transition to the interior and extinguish the fire," said District Chief Harris. As they tried to help those who were affected by the overnight fire. Three injured after overnight house fire in Edmond "We reached out to Red Cross for assistance for all the occupants that have been displaced from their residence," said District Chief Harris. Right now, it's still unclear how the fire started. "We do have investigators on the way to further look at this and try to determine what the origin was and what was the cause of this fire," said District Chief Harris. Fire crews said everyone who evacuated was checked by EMS and is okay. District Chief Harris also wants to remind the public that closing doors in your house can help stop or delay a fire from spreading. He said some doors stayed closed in this apartment fire, which helped crews put it out faster.