A massive explosion that leveled the home of an interracial couple in Sterling, Ohio, this week is being investigated as a possible hate crime after officials found a crude swastika and misspelled anti-Black slur spray-painted next to the scene.

The home, about 25 miles west of Akron, was unoccupied when it was destroyed early Wednesday. There are no reported injuries.

Local police are investigating with the help of federal officials, Wayne County Sheriff Captain Doug Hunter said Wednesday in a video update posted to Facebook.

After 23 years, the homeowners Angela and Brad Frase were just one year away from paying off their mortgage, Angela Frase told the Akron Beacon Journal. She is Black and he is white.

The Frases had not been staying in their home for the past month after an electrical fire in early July caused enough damage for the couple’s insurance company to put them up in a nearby hotel. The home was being repaired and they planned to move back in September.

Frase told a local Fox affiliate that she felt “total disbelief that there’s still this much hatred in America.” She became physically sick after hearing the news about her home.

“We decided that whatever happens, we’re not rebuilding here,” Frase told news station. “We’re not coming back. We’re done.”

One day before the explosion, Hunter said, construction workers in the home reported a strong smell of natural gas and a quick investigation determined that a stove burner had been left on. The gas company servicing the home cut the supply, but according to Frase, investigators said there would have been enough gas left in the house for it to ignite with a simple cigarette spark.

The sheriff noted that the Frases told him they had experienced no prior hateful incidents in the neighborhood.