Ultimately, the swift sinking and immense loss of life can be attributed to three factors: the location in which "Storstad" made contact, failure to close "Empress of Ireland"s watertight doors, and longitudinal bulkheads that exacerbated the list by inhibiting cross flooding. A contributing factor was open portholes. Surviving passengers and crew testified that some upper portholes were left open for ventilation. The International Convention for the Safety of Life at Sea (SOLAS) requires that any openable portholes be closed and locked before leaving port, but portholes were often left open in sheltered waters like the Saint Lawrence River where heavy seas were not expected. When "Empress of Ireland" began to list to starboard, water poured through the open portholes further increasing flooding.