The National Transportation Safety Board released the preliminary report for a Delta Air Lines flight from Atlanta to Charleston that had to be evacuated after smoke filled the cabin.

No oil was visible in the gauge on the right engine’s oil reservoir after a February Delta Air Lines flight filled with smoke during takeoff at Atlanta’s Hartsfield Jackson International Airport, a preliminary report from the National Transportation Safety Board said Wednesday.

After a Delta flight made an emergency landing in Atlanta​ in February, a maintenance crew found there was barely any or possibly no oil in the aircraft's right engine, an NTSB report said.