YARMOUTH — In some ways, it was a typical summer scene.

Mary Halsey sat under a shade tree Monday and sipped water while her baby granddaughter cooed in a nearby pram. An occasional breeze cut the humid air and rustled the leaves hanging over Halsey’s head.

But this was no ordinary summer scene.

Aside from a small patch of green grass under her feet, Halsey sat within a massive swath of destruction.

Behind her loomed three condemned homes, broken trees and piles of splintered lumber. Throughout the neighborhood, homes were boarded up, tattered and encircled by long strands of yellow caution tape. Behind her house, jagged sheets of particleboard dangled from boughs high atop old-growth spruce trees. Two doors down, an American flag billowed at half staff.

Every day for a week, the recently widowed Halsey has sat in this tidy oasis of green grass to reflect on a difficult year and to wait for her cat to come home.

Halsey last saw Joey, an orange tabby, on the morning of June 25 when he begged to be fed. A few minutes later, a massive explosion tore off the northeastern wall of Halsey’s new home.

A neighborhood transformed

Five people were displaced when the condominium at 50 Gables Drive exploded and killed its lone occupant, 66-year-old Peter Corey. Four people received minor injuries. More than a dozen buildings were damaged, including some 200 yards away.

Investigators are still trying to determine the source of the blast but it was probably fueled by propane, according to Sgt. Ken Grimes, an investigator at the state Fire Marshal’s Office. They have removed propane appliances and piping from the blast site to determine whether a leak is to blame.

Gables Drive is a quiet, dead-end street with 14 condominiums in seven duplexes. Since the explosion, three units have been declared uninhabitable, including Corey’s, which was obliterated in an instant. One more might be added to the list. Three units are still off limits to their owners.

The remaining eight units have been reopened, according to Jeff Martin, president of Foreside Real Estate Management, the company that maintains the shared property at North Gables Condominiums.

The total cost of the destruction isn’t yet known. Damage to town properties — the nearby garage and fire station — is minimal and probably wouldn’t exceed the insurance deductible, Town Manager Nat Tupper said.

Damage to privately owned structures will be much, much more costly.

Insurance adjusters are still crunching the numbers, but the total will be “in the millions,” said John Wentzell, president of the North Gables Condominiums Association.

Before the explosion, the market value for a condo on Gables Drive was about $400,000.

“With three units at $400,000, that’s $1.2 million right there,” he said. “Then you’ve got 11 more units with varying degrees of damage.”

Each structure is insured through the condo association. Residents insure their belongings through their own policies, Wentzell said.

It’s unknown how long it will take before everything returns to normal, Wentzell said. How long will it take to remove the debris from 50 Gables Drive, to raze the units at 36 and 52 and rebuild all three?

A year? 16 months? Longer?

In the meantime, Wentzell said it’s doubtful the neighborhood will ever know what happened in Corey’s unit that morning. There might not be enough evidence for investigators to reconstruct the events, but there will be speculation, he said.

Corey was a mystery to many neighbors on Gables Drive. He wasn’t well known but he was a source of concern. Corey had physical and mental disabilities, and some people weren’t convinced he could or should live independently, Wentzell said.

In Corey’s obituary, his family describes him as a happy, helpful man who looked after his parents in Cape Elizabeth until they died in their 80s.

Corey helped bring adaptive golf to Maine Adaptive Sport and Recreation, according to the obituary. He also led an active daily life.

“Peter treasured the condo at North Gables in Yarmouth, where he was devoted to his beloved sister-in-law, Julie Corey, who dropped him off at the Cumberland County YMCA every day of the week,” the obituary states.

Despite daily contact with family, not everyone was convinced Corey was all right on his own. At one point, Wentzell expressed the neighborhood’s worries to Corey’s brother, Walter Corey, who owns the property at 50 Gables Drive.

“Walter told me Peter was just fine on his own,” he recalled.

The explosion might be proof to the contrary, Wentzell said. Nonetheless, the condo association isn’t planning any legal action.

“It hasn’t been discussed at all,” he said. “I’m not saying it never will be, but right now we’re more worried about our immediate needs, like getting everything back to the way it was.”

An unlucky year

Halsey hadn’t met Corey. She barely had the opportunity. She had only lived in the neighborhood for two days.

“On the morning of the third day, it blew up,” she said.

Halsey chose Yarmouth after her husband died of leukemia in February, just two weeks after their 40th wedding anniversary. She wanted to live closer to her daughter’s family in Portland and her sister’s family in Bangor.

Halsey’s furniture hadn’t even arrived from her previous home in York, Pa. For the time being, it was just her, an air mattress, some clothes and her two cats.

On the morning of the explosion, Halsey left her first-floor bedroom and walked to the kitchen to feed the cats. When she noticed it was only 6:17 a.m., she decided to go back to bed — a lucky decision in an otherwise unlucky year, she said.

Halsey had returned to her air mattress for just a few seconds before the house shook, shards of glass rained onto every floor and sunlight poured into the house through a massive hole where an exterior wall once stood. Wall boards buckled, garage doors caved and support beams sheared in half. The urn containing the cremated remains of her husband, Dennis, shattered.

Halsey escaped the home by prying open a damaged garage door and squeezing through. Then she was taken to a hospital for observation.

Later, rescuers found one of her cats alive beneath collapsed wall board. Her other cat, Joey, hasn’t turned up. Some people claim they’ve seen the orange tabby near the ball fields on the other side of North Road, but he’s been too skittish to catch.

Joey is 4 years old, but he’s new to Halsey. A few weeks before her husband died, the couple decided to adopt two adult cats from the same litter. It was one of their last shared decisions, she said.

Halsey is now trying to decide her next step. She’s looking to rent an apartment or a house while hers is being replaced. In the meantime, she plans to continue her daily vigil for Joey while it’s still reasonable he might return. Each night she puts out food for him in the garage, the one part of the house that is still stable.

She remains hopeful.

“I’ve had some rotten luck,” she said with a laugh. “But things are going to get better. I just know it.”

Ben McCanna can be reached at 781-3661 ext. 125 or bmccanna@theforecaster.net. Follow him on Twitter: @BenMcCanna.