Dozens of people were evacuated from their homes after a gas main fire.
The incident occurred at 1.40am on Saturday in Coney Green Drive, a residential street in Longbridge, Birmingham.
Firefighters called to the scene found a man slumped unconscious in a gas main trench, and rescued him while the fire blazed nearby.
He was taken to hospital and held on suspicion of starting the fire, West Midlands Police said. No-one else was injured.
Emergency services set up a 50m cordon around the trench, and a second gas leak was found in an adjoining road, Hawkesley Crescent, triggering a second cordon.
Roads were closed and 45 people evacuated from their homes as emergency services tackled the fire and gas leaks, West Midlands Fire Service (WMFS).
Extra police were brought in to assist with what officers declared a "critical incident" due to the impact on the community and police resources.
A WMFS spokesman said: "Police, the fire service and ambulance crews are working with the gas board who are trying to repair this leak so that they can put the fire out."
A police spokesman later said that evacuated residents had been allowed to return to their homes shortly after 6am.