Since an explosion rocked a Plano neighborhood last Monday — leveling one house, spraying building material across the subdivision and hospitalizing six people — residents have been left wondering what caused the destruction.

Some suspected a lightning strike from a storm that was overhead shortly before 5 p.m., when the blast occurred. However, authorities indicated the following day that an isolated gas leak was to blame.

Then an update from police Wednesday suggested a different answer — while raising even more questions. “After further investigation, it was determined the explosion may have been intentional,” according to the short written statement from a spokesman for the Plano department.

Days later, authorities still have yet to explain who might be responsible.

Blast was felt up to a mile away

Besides toppling the one home, the explosion severely damaged two others and shattered windows throughout the neighborhood near Ohio Drive and West Park Boulevard.

When people called 911, some of them described the hardest-hit home as “completely gone,” Plano Fire-Rescue Capt. Peggy Harrell said.

A large piece of roof was left embedded several inches into the yard of a home across the street. Neighbors farther away reported broken glass and cracked skylights.

One man told The Dallas Morning News that he felt the blast at a Dairy Queen nearly a mile away.

When authorities initially blamed an isolated gas leak, it was a reminder of other explosions in North Texas.

In February 2018, a natural-gas explosion lifted a home in northwest Dallas off of its foundation. A 12-year-old girl, Linda “Michellita” Rogers, was killed.

Last month, two people died in a Collin County natural-gas explosion that authorities said occurred as subcontractors for Atmos Energy were performing maintenance on a pipeline.

Injured include family next door

Last week’s explosion injured the man who lived at the destroyed home in the 4400 block of Cleveland Drive, as well as the family who lived next door.

Joseph Kupfer was inside the home that exploded, his attorney, Scott J. Becker, told WFFA-TV (Channel 8). Becker said last week Kupfer was “fighting for his life.”

The family next door— Jennifer and Philip Jagielski and their three children — were also hospitalized, according to a GoFundMe page.

The children were released from the hospital the day after the explosion. Jennifer was released Wednesday. Philip is recovering from emergency surgery, according to the most recent update from the fundraiser.

Investigation continues

Since suggesting the explosion may have been intentional, Plano police have declined to release more information.

Although authorities have indicated that crews from the FBI and Bureau of Alcohol, Tobacco, Firearms and Explosives, along with the police and Plano Fire-Rescue, have been involved in the investigation, no officials have publicly explained where the blast originated and whether a suspect has been identified.

Plano police did not respond to a request for information Sunday.