Infrastructure losses, damaged buildings and power cuts reported around Baja California region

Initial reports from the April 4 Mexico earthquake suggest that the majority of the damage is focused around the city of Mexicali which has a population of around 1.2 million.

Officials and media have reported damage to buildings, cracked roads, ruptured water canals, and power outages following the magnitude 7.2 earthquake.

An undetermined number of homes, offices and hospitals have been damaged, according to catastrophe modelling company RMS. However, no loss estimates are available yet.

The Baja California Governor Jose Guadalupe Osuna requested a state of emergency in Mexicali on Monday, 5 April. In total there have been two fatalities and at least 200 injuries resulting from the earthquake, all of which are in Mexico.

Also in Mexicali, several fires were caused by ruptured gas lines and people were reported to be stuck in collapsed buildings. Television reports show damaged buildings, cracked roads and toppled telephone poles. A state government building under construction was also damaged.

Reports from Mexican and US authorities suggest there were more than 100 aftershocks of between magnitude 3.0 and 5.4 up to early Wednesday morning, causing further concern and interrupting damage assessments.

According to the US Geological Survey PAGER system (Prompt Assessment of Global Earthquakes for Response), Mexicali was subject to shaking of intensity VII (‘very strong’) on the MMI scale, which has the potential to cause moderate damage to resistant structures and moderate/heavy damage to vulnerable structures.

Damage reports are also emerging from the US side of the border, specifically from the city of Calexico (population around 36,000) where reports focus on damage to buildings facades, shattered windows, fallen brick and plaster from structures and some contents damage. The city council of Calexico declared a state of emergency on Monday, 5 April.

The earthquake occurred in the Baja California region of northern Mexico at 22:40 UTC (3:40 pm local time) on Easter Sunday April 4.

The US Geological Survey (USGS) released an epicentral location of 32.128°N and 115.303°W, approximately 16 miles (26 km) from Guadalupe Victoria, Baja California; 38 miles (60 km) from Mexicali, Baja California; and 104 miles (167 km) from Tijuana, Baja California. This event was a shallow crustal earthquake with a focal depth from the USGS estimated at 6 miles (10 km). Shaking was felt widely throughout northern Baja California, southern California and southwest Arizona. The USGS ShakeMap indicates that the region in the immediate vicinity of the epicenter experienced up to intensity IX shaking on the Modified Mercalli Intensity Scale (MMI). This region is sparsely populated, with USGS PAGER system estimating that only 500 people may have been exposed to this degree of ‘violent’ shaking.