Two men, trapped while working in an underground tank at a filling station in Lagos died on Friday, the News Agency of Nigeria (NAN) reports.
The director of the Lagos State Fire Service, Rasaq Fadipe, confirmed the development in an interview with NAN.
He said the men were working on routine maintenance of the tank when the incident happened.
Mr. Fadipe said the men were working at Fatgbems Filling Station at Ojodu, Berger before one of them got trapped in the tank.
He said the men died before fire servicemen could rescue them.
"We got the call at about 7.09 a.m. We were told that one of the men inside the underground tank shouted for help but later collapsed.
"The second man, who was the supervisor for the work, decided to go and rescue them against people's advice and he also inhaled fuel fumes from the tank and collapsed.
"Our men brought out their dead bodies and handed the body over to police officers from the Ojodu Division, who later took them to the mortuary," Mr. Fadipe said.
He advised members of the public against putting their lives in danger, saying that rescue operations should be left for professionals.