“There's been a big oil spill off the coast of Louisiana.”

You are watching the news on TV and they're talking about an oil spill. Your roommate walks by and sees the pictures. He hasn't heard about this news, so he asks what's going on. You say:

There's been a big oil spill off the coast of Louisiana.

There's been (an event)

You use "There's been a ___" to describe an important event that has happened. For example:

There's been a murder.

There's been an earthquake in San Francisco.

oil spill

An "oil spill" is when a large amount of oil leaks out into the ocean from a crashed oil tanker (a boat that carries oil), a broken oil pipeline, or from an offshore drilling location.

off the coast of (somewhere)

This phrase describes a location in the ocean that's away from the land but close to a certain continent, country, state, province, island, etc.:

off the coast of South America

off the coast of Maui

off the coast of California