At around 10 p.m CST on April 20th, there was an explosion aboard the Deepwater Horizon, an ultra-deepwater, dynamically positioned, semi-submersible offshore drilling rig. The explosion was caused by a blowout after a gas bubble came up the pipeline, bursting through several seals and barriers. Ordinarily, pressure management systems would prevent this kind of event, but on the Deepwater Horizon, those systems failed. What lessons does the Deepwater Horizon teach small businesses?