A suspected gas explosion tore through four residential buildings on Saturday evening in the southern town of Ravanusa, with one survivor describing it "as if a bomb had gone off."

A flower is seen amongst the rubble at the site of a gas explosion that caused several houses to collapse in Ravanusa, Italy, Dec. 13, 2021.

Around 100 emergency workers have been picking their way through the rubble ever since, in what firefighters said was a "delicate and complex" operation.

Members of a rescue team work at the scene of a gas explosion in a residential building, in Ravanusa, Italy, Dec. 12, 2021.

Rescuers work at the site of a gas explosion that caused several houses to collapse in Ravanusa, Italy, Dec. 12, 2021.

This handout picture taken and released by the Italian Firefighters (Vigili del Fuoco) on Dec. 13, 2021, shows firefighters searching rubble after a four-story apartment building collapsed on Dec. 11 in Ravanusa, Sicily.

Rescuers work at the site of a gas explosion that caused several houses to collapse in Ravanusa, Italy, Dec. 12, 2021.

Members of a rescue team work at the scene where a four-story building collapsed following a gas explosion, in Ravanusa, Italy, Dec. 12, 2021.

Rescuers work at the site of a gas explosion that caused several houses to collapse in Ravanusa, Italy, Dec. 12, 2021.

People gather as members of a rescue team search for victims in the aftermath of a gas explosion in a residential building, in Ravanusa, Italy, Dec. 12, 2021.

A rescue team searches for missing residents after a four-story building collapsed following a gas explosion, in Ravanusa, Italy, Dec. 12, 2021.

Members of a rescue team search for victims in the aftermath of a gas explosion in a residential building, in Ravanusa, Italy, Dec. 12, 2021.

Members of a rescue team work at the scene of a gas explosion in a residential building, in Ravanusa, Italy, Dec. 12, 2021.

Members of a rescue team work at the scene of a gas explosion in a residential building, in Ravanusa, Italy, Dec. 12, 2021.

Members of a rescue team work at the scene of a gas explosion in a residential building, in Ravanusa, Italy, Dec. 12, 2021.

Security tape is set up at the scene where a four-story building collapsed following a gas explosion, in Ravanusa, Italy, Dec. 12, 2021.

A relative sits after several buildings collapsed following a gas explosion, in Ravanusa, Italy, Dec. 12, 2021.