The US Capitol has been placed on lockdown and people attending a rehearsal for the Inauguration were evacuated due to an "external security threat."
According to Capitol Police, "In an abundance of caution following an external security threat under the bridge on I-295 and First and F Streets, SE, Acting Chief Pittman ordered a shutdown of the Capitol Complex. There are currently no fires on or within the Capitol campus. Members and staff were advised to shelter in place while the incident is being investigated."
The memo also adds that more information will be shared shortly.
Reports of smoke rising from a homeless encampment nearby lead to the speculation as to why the rehearsal was evacuation. DC Fire and EMS sent out a tweet, saying they "responded to an outside fire in the 100 block of H St SE that has been extinguished. There were no injuries. This accounts for smoke that many have seen."