Maracaibo: oil city
Maracaibo was isolated from the rest of Venezuela across a large lake and closer therefore to Colombia, until El Puente Sobre el Lago was built by the Jiménez regime of the 1950s. A competition had been set in 1957, and won by Riccardo Morandi, an Italian structural engineer, who designed it in concrete. It was the longest prestressed concrete bridge at the time, 8.67km.
Maracaibo is the oil city of Venezuela; the lake is attached to the Maracaibo Basin, part of the Gulf of Mexico and the site of Venezuela's oil reserves. In 1964 part of the bridge collapsed after being hit by an Esso oil tanker. There wasn't a resultant oil spill, however there is no such thing as failsafe oil transport.
The Esso Maracaoibo II, the tanker, had been the US Navy gasoline tanker, USS Narraguagas. It had been bought by the Compania de Petroleo Lagos in 1947, so the US Navy must have been decommissioning its support fleet after WWII. It ferried crude oil from Lake Maracaibo to a refinery at Aruba. At the time of the accident it had 236,000 barrels of crude on board; an electrical failure occured and the tanker drifted, smashing into the bridge and a 248m section collapsed. Seven people, in four cars, fell off the bridge and died.