LA GUAIRA, Venezuela (AFP)—Hopes were fading Monday of finding survivors more than four days after powerful twin earthquakes struck Venezuela, as residents grow increasingly frustrated with the government’s response to the disaster that has killed at least 1,450 people and left tens of thousands unaccounted for.

French and American rescue teams found a man and his teen son alive under the rubble on Sunday in Caraballeda, a town about 40 kilometers (25 miles) north of Caracas, AFP journalists saw.

The rescue offered a glimmer of hope in an ongoing tragedy that has shaken a country already mired in an economic crisis, but that hope dwindled as the critical 72-hour window for rescuing trapped victims passed.