Nothing happened. Twenty minutes later, they decided that the fuse was a dud and went back to try again.
Presumably neither was aware of the chemical friendship between oxygen and fire. As they lifted the lid the entire washer exploded, landing them both in the hospital for several days. Shrapnel from the washer spread in a 25-ft radius, leaving a large crater in its wake. Considering the impact crater, each perpetrator suffered relatively minor wounds and burns.
Category: tool, holiday, fireworks