A large earthquake rocked the area of Baja California at 3:40 p.m. on Sunday afternoon. The 7.2 magnitude quake killed at least two people, caused damage to buildings in the city of Mexicali, Mexico, and jolted millions of people across Southern California. A quick guide to the strongest earthquake to hit the area for 18 years:

Where was the epicenter?
Thirty eight miles to the southeast of the city of Mexicali in Baja California, Mexico. The city sits on the American border around 110 miles east-southeast of Tijuana.

How far away was it felt?
The quake caused high rise buildings to sway in San Diego and Los Angeles, while shocks were reported as far away as Las Vegas and Phoenix.

How bad was it?
At 7.2 magnitude, the quake was the strongest to impact the region since the 7.3-magnitude Landers earthquake in 1992. Amateur videos shot during the event show how some Southern Californians experienced the temblor:

What city has been the hardest hit?
Mexicali, a commerce center that sits on the US border with a population of around 900,000. A multistory parking facility was amongst several buildings to collapse as a result of the quake, and the entire city lost power during the tremor. The adjacent city of Calexico, on the U.S. side of the border, also suffered damages.

What are the casualties?
Two men from Mexicali are reported to have died; one when his house collapsed on him, and another who was struck by a car during the temblor. More than 140 people were hospitalized, and five reported to be in critical condition. Several Calexico residents were injured, but not severely.

Have there been any aftershocks?
There were three strong aftershocks within the hour, according to the U.S. Geological Survey, the worst of which was a 5.1 magnitude tremor in Imperial County, San Diego. Another strong aftershock hit the Baja California area in the early hours of Monday morning.

Why wasn't the impact worse?

Although it was an extremely strong quake (only the 18th 7.0+ quake to be recorded in California in its history) the damage was limited because the quake's epicenter was only six miles underground.

Sources: CNN, LA Times, Christian Science Monitor, USGS