LINCOLN (CBS/AP) – Thousands of evacuees are returning home after fire crews allowed a burning propane rail tanker to burn itself out, ending the threat of a major explosion in the city of Lincoln.

Fire Chief Dave Whitt said a mandatory evacuation was lifted around midnight, allowing residents in nearly 5,000 homes to return home.

It remains unclear how the tanker caught fire Tuesday at the Northern Propane Energy facility, about 30 miles northeast of Sacramento.

The fire had burned out before midnight, but then crews reignited it to allow vapors caught in the tank to also burn away.

Whitt said the tanker was being filled with water and a small amount of foam. He said crews used up to 5,000 gallons of water per minute to keep the tank cool.

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