Louisville Emergency Management officials will meet this afternoon with the National Weather Service to discuss why the city's tornado sirens didn't sound yesterday morning.It's possible a technical malfunction caused MetroSafe radios to miss the National Weather Service tornado bulletin and sound the sirens. However, some city officials and citizens have asked why the sirens were not manually activated by a MetroSafe employee.The city is investigating the issue and today's meeting with the weather service is part of their research. It's possible a final answer will be known today, though a spokesperson for the mayor's office says more investigation may be needed.