Massive explosion rocks Hotel in Fort Worth, Texas (video)

There has been an explosion at the Sandman Signature Hotel in downtown Fort Worth, Texas. 

Authorities and other law enforcement personnel raced to the scene of the gas explosion after the first call came in at 3:32p.m on Jan. 8.

Emergency responders have declared a mass casualty incident. 

At least 21 are reported to have been injured. 

Footage from the scene shows windows blown out and a possible floor collapse in the interior of the hotel located at 810 Houston Street. 

Numerous witnesses have reported hearing the explosion miles away. Police are urging everyone to avoid the area. 

Public Information Officer for the Fort Worth Police Department, J. Pollozani said 21 people were injured. Pollozani said one patient is critical and four were seriously injured. 

According to FWFD, 19 patients were treated on the scene, one took themselves to a hospital and there are not any deceased officials are aware of at this time. 

Three of those injured were employees of Musume, the restaurant inside the Sandman Hotel. 

The hotel was operational at the time of the explosion and there were 26 rooms occupied.

Watch a video from the scene below.