A bulldozer clears away debris after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
A bulldozer cleans up debris after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
Rescue workers treat an injured person after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015, after a powerful tornado touched down. The tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
People stand near damaged homes and vehicles after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
Residents clear away debris from their home after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
A man stands in debris next to damaged homes after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
Soldiers stand next to damaged homes after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
A bulldozer clears away debris after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
A vehicle lies on the rooftop of a home after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through a city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
Damaged homes stand next to others that were razed when a powerful tornado touched down in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. The tornado raged through the city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)
A vehicle lies on the rooftop of a home after a powerful tornado swept past in Ciudad Acuna, northern Mexico, Monday, May 25, 2015. A tornado raged through a city on the U.S.-Mexico border Monday, destroying homes and flinging cars like matchsticks. At least 13 people were killed, authorities said. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated." (AP Photo)