An explosion at a historic Texas hotel in Fort Worth on Monday blew out windows, littered downtown streets with large piles of debris from the building and injured 21 people, including one person who is in critical condition, authorities said. Rescue crews found several people trapped in the basement of the 20-story hotel that is in the heart of downtown Fort Worth.

Craft Trojacek a spokesman - for the Fort Worth Fire Department, said the blast flung doors and entire sections of wall onto the road in front of the hotel and more than two dozen rooms were occupied at the Sandman Signature Hotel. Texas State Representative Nicole Collier said she heard the sirens of responding emergency vehicles and helicopters overhead. Federal Investigations are underway to determine the cause of the blast. The building has been listed on the National Register of Historic Places since 1979.