(Fort Pierre, SD) — It’s now known what was the likely cause of the deadly house explosion southeast of Fort Pierre on May 24th. The Stanley County Sheriff’s Office says a gas leak may be to blame for the explosion that killed three people. Officials believe liquified petroleum gas made its way into the basement of the home. The Sheriff’s Office says damaged piping and components are undergoing lab examination as the investigation continues. The cause of the ignition is still unknown at this time, but the explosion has been ruled accidental.