A Mexican news station was broadcasting live when the 7.1-magnitude earthquake struck. Footage shows studio equipment and lights swinging violently as the anchor and staff run out of the studio. A warning siren is heard in the background as the studio camera goes off-air. The earthquake was the deadliest to hit Mexico in more than 30 years. It has flattened buildings and sent masonry tumbling on to streets, crushing cars and people in the capital, Mexico City, and neighbouring areas