LAWRENCE — The process of removing travel trailers placed on the South Common for local gas disaster victims started Thursday morning.

Mayor Daniel Rivera said some of the trailers are now being sent to California, where 88 people have been killed and thousands have been left homeless, their homes destroyed by wildfires.

The travel trailers were brought to the Merrimack Valley in mid-October after thousands of local residents were left without natural gas for heat and cooking a month earlier.

On Sept. 13, a series of explosions and fires forced natural gas to be shut off to thousands of homes and businesses in South Lawrence, Andover and North Andover.

Columbia Gas, the utility provider, is hoping to have gas restored to everyone affected by Dec. 16.

Rivera said that starting Thursday morning, work would begin to remove trailers parked on the South Common near South Union Street. Those trailers have been empty and unused, Rivera said.

He stressed that any trailer being used by residents needing shelter "will not be removed" until those people have gas service fully restored to their homes.

"No, that won't happen until they are re-lit," Rivera said of used trailers being removed from the common.

Rivera described the removal of the trailers "as definitely a good sign."

"It means there are more people back at home with heat and hot water," he said.

Hundreds of travel trailers for displaced residents were brought to both the South Common, Pemberton Park and O'Connell Park in Lawrence.

Trailers were also brought to Grogan Field in North Andover and Andover's Recreation Park as part of the alternate housing plan.

In coming days, unused trailers will also be removed from those locations, officials said. 

North Andover Town Manager Andrew Maylor on Wednesday announced that Grogan Field would be "decommissioned" as a trailer site starting on Dec. 3. 

Removing the travel trailers and related equipment from the area could take seven to 10 days, said Maylor, in a tweet.

Rivera said any damage to South Common will be repaired and improved in coming months. 

"Columbia Gas will pay for it," he said. 

The travel trailers were all part of Columbia Gas' "temporary housing plan" following the Sept. 13 gas disaster. Hotel rooms, apartments and trailers were available to gas customers.

As of Thursday, 2,274 families (8,037 individuals) total had been placed in temporary housing, according to a daily update released by Columbia Gas. Some 1,013 families were still in temporary housing.

Some "1,261 families have returned home from temporary housing and have restored gas service," according to the update. 

As of Nov. 27, 2,672 hotel rooms, 40 apartments and 94 trailers were available to customers in need.

To date, Columbia Gas has received 23,981 claims and paid out $66.56 million.

And, some 6,463 of 7,400 residential gas meters (serving about 10,000 dwellings) and 641 of 685 business gas meters have been restored, according to Columbia Gas. 

Follow staff reporter Jill Harmacinski on Twitter @EagleTribJill.