Tonnes of dead fish - level 2
Thousands of dead fish appeared in a lagoon in Mexico. People removed nearly 50 tonnes of fish in just two days.
The incident started an investigation into local wastewater treatment plants. The fish probably died of high pollution, but everybody says something different. Some locals say it was a naturalphenomenon, but the government rejects this.
Difficult words: wastewater treatment plant (building which cleans water), pollution (dangerous waste from people or animals), phenomenon (something which happens in nature).