Twin earthquakes rocked Venezuela on Wednesday evening, collapsing entire apartment buildings across Caracas and leaving behind scenes of widespread devastation.The USGS said the first quake registered a magnitude of 7.1, with an epicenter near Morón, about 104 miles west of Caracas, at a depth of 8 miles. One minute later, a similarly massive magnitude 7.5 quake struck nearby, roughly 10 miles southwest of Morón, at a depth of 6 miles. Remarkably, the dual quake was followed almost immediately across the world by a 6.9 magnitude temblor in northern Japan, which rattled buildings in Tokyo.USGS issued a red-alert mass-casualty warning due to the combination of shallow depth, heavy population exposure, vulnerable buildings, and estimated losses large enough to require an international response."Red alert for shaking-related fatalities and economic losses. High casualties and extensive damage are probable and the disaster is likely widespread. Past red alerts have required a national or international response," USGS said, adding, "Estimated economic losses are 2-20% GDP of Venezuela."In the Palos Grandes neighborhood in eastern Caracas, residents tried frantically to rescue people trapped under the debris of collapsed buildings, Bloomberg reports. Terrified families remained in the streets as the capital was hit by aftershocks. Venezuelan migrants in Colombia and elsewhere sought to reach relatives, but cellphone coverage was down in swathes of the country.The early footage emerging from the devastation is dramatic:Devastating scenes emerge from La Guaira, Venezuela, following a powerful earthquake that struck the region. pic.twitter.com/fBMIDWuabP