Baja California state Civil Protection Director Alfredo Escobedo said the man's home collapsed just outside of Mexicali, close to the epicentre of the 7.2-magnitude quake. Esobedo says there were reports of more people trapped in homes in Mexicali and rescue teams with dogs and digging equipment are rushing to the city from nearby Tijuana.
The quake, which struck at 2240 GMT (8.40am), was at a depth of 32.3 kilometres and was located 26 kilometres south-south-west of Guadalupe Victoria, Baja California, and 64 kilometres south-west of San Luis, in the US state of Arizona, the USGS added.
A number of San Diego residents said the quake was the worst they had felt in decades.
Jess Ponting, an Australian working at San Diego State University, said he was at home when the quake struck. "The main earthquake shook our apartment block and caused a panic up and down the street,"
"I cowered under my kitchen table on the third floor for about 45 seconds as the apartment shook violently and glassware rattled and ornaments and pictures fell off the walls. "After the tremor finished, everyone spilled out on to the streets and started calling loved ones and figuring out what was going on."