SANTA ANA, Calif. — An intense rotten egg smell that had Southern Californians plugging their noses and crying foul Monday was coming from the Salton Sea.

Air quality investigators confirmed Tuesday that the foul stench that stretched across Southern California was the result of a huge fish die-off at the saltwater lake 150 miles southeast of Los Angeles.

The aroma was analyzed by officials from the South Coast Air Quality Management District, who collected air samples and modeled wind patterns. The air samples showed that hydrogen sulfide levels were highest around the lake and grew weaker at longer distances

Officials had received 200 complaints from across much of the district’s 10,000 square miles.

“The odor was extremely intense,” said Janis Dawson of the Salton Sea Authority. “We actually thought that somebody had an accident, a broken sewage main, that’s how strong it was.”

The dying sea, a major resting stop for migrating birds on the Pacific Flyway, has been plagued by increasing salinity. Created in 1905 when floodwaters broke through a Colorado River irrigation canal, it’s expected to shrink significantly by 2018 and become even saltier.

The sea had a fish die-off within the past week and that, combined with strong storms in the area late Sunday, likely churned up the water and unleashed bacteria from the sea floor that caused the stench, said Dawson.

The massive thunderstorm complex moved from Mexico over the area Sunday night, with wind gusts up to 60 mph and widespread dust storms.

“We were watching it from the office on our satellite radar and it was huge, one of the largest that any of us have ever seen in probably 10 years,” said Mark Moede, a National Weather Service meteorologist in San Diego.

The smell doesn’t pose any health hazards, but it generated an explosion of quips on social media from Riverside County to the San Fernando Valley north of Los Angeles.

Jose Chavez, a 28-year-old comedian from San Fernando, tweeted: “The Valley is starting to smell like rotten eggs. In an unrelated note, Febreeze sales are through the roof in the San Fernando Valley.”

Chavez was leaving the grocery store when he was overwhelmed by the odor, he said in a phone interview.

“My first thought was that maybe one of the eggs I bought was rotted and I got back home and the smell was still there so then I started to think it was me so I changed my clothes,” he said. “It was very pungent.”

Jack Crayon, an environmental scientist at California’s Department of Fish and Game, said he recognized the smell as the typical odor when winds churn up the sea’s waters and pull gases from the decomposition of fish or other organisms up to the surface.

He said the phenomenon typically occurs a few times a year in the area surrounding the lake, but it was unusual for the smell to spread so far.