In California, the latest earthquake to hit the state has killed at least 20 people and left dozens of others injured.
The earthquake, which happened at 5:16am (0716 GMT), shook a swath of the state near the Mexican border, killing at least 19 people and leaving hundreds more injured.
It was the strongest quake to hit Mexico in nearly two decades.
More:The US Geological Survey has recorded 7.8 quakes in the past six months, more than twice the average of 1.2 quakes per month, and there have been at least four more in the state in recent weeks.
According to the USGS, the quake was centered about 30km (19 miles) north-east of San Francisco.
It is the strongest earthquake to occur in the US since the 1950s.
At least two other powerful quakes struck the region last month.