United flights into Los Angeles have resumed after a gas leak halted all inbound planes and left a worker in critical condition

• An gas leak caused disruptions at Los Angeles International Airport's Terminal 8 on Monday.
• Passengers were evacuated from the terminal and United Airlines halted some flights for a time.

A carbon dioxide leak on Monday halted all incoming traffic for a time at Los Angeles International Airport and left one airport worker in the hospital in critical condition.

The incident forced passengers to evacuate LAX Terminal 8, which serves United Airlines. Meanwhile, United said that it would temporarily consolidate its operation to Terminal 7 because of the carbon dioxide issue.

Brian Humphrey, a spokesman for the Los Angeles Fire Department, told Insider that the carbon dioxide discharge was an accident — and was tied to a fire-suppression system in the airport. Four workers at LAX were in a utility room that contained mostly electrical equipment when the carbon dioxide was discharged from the fire-suppression system in that room, Humphrey said.

One of those workers, who Humphrey described as a man in his mid-50s, went into cardiac arrest and was sent to the hospital in grave condition, but has since been listed in critical condition, the spokesman said. He said it wasn't clear what had triggered the accident.

Since the incident, the LAFD said it "closely examined the area with sophisticated instruments, and discovered only trace residue of carbon dioxide remaining within the utility room." There was nothing found to escalate the situation, the department said.

Meanwhile, the incident triggered a full ground stop at the airport for part of the morning, with United Airlines and its regional carriers affected. All other flights and terminals were operating as normal, the airport said.