In a short message sent from his @Pontifex Twitter account, the pope told the more than 2.3 million followers on his English account to "Please join me in praying for the victims of the explosion in Texas and their families."

A massive explosion ripped through a fertilizer plant about 75 miles south of Dallas the evening of April 17, killing at least five people and wounding more than 160 others. The number of casualties was expected to rise, authorities said.

The blast leveled dozens of homes nearby and seriously damaged other buildings, including a nursing home. Nearly half of the town's 2,800 residents were forced to evacuate over fears that another fertilizer tank might explode and because of the danger posed by the chemicals' noxious fumes.