Lake Pontchartrain is north of New Orleans. He said they were doing maintenance work when the fire started, but he said he did not know the precise nature of their duties.
Police are not releasing the names of any of the victims at this time, but so far there are no reports of any fatalities.
Officials have said the fire erupted Sunday night, burning natural gas that powers some of the platform's equipment.
The Coast Guard will be conducting a water quality evaluation as well as the Lake Pontchartrain Basin Foundation.
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Sheriff Joe Lopinto of Jefferson Parish said that the search of Lake Pontchartrain would continue for "as long as it takes". Authorities say there has been no reports of building damage on shore. Two of the three people in critical condition were in a burn unit, Guilot said. There is no active drilling on the lake, according to Jean Kelly of the state environmental department. The platform is located in shallow water about a mile and a half from the Kenner boat launch. The Kenner government Facebook page said authorities on the scene reported that cleaning chemicals had ignited on the structure, but the company said the cause of the blast was unknown.
The Deputy head of the administration of Jefferson parish also reported that the incident injured seven people. Arson investigators will determine the cause after the fire has burned out.
U.S. Coast Guard crews hoped to get a helicopter into the air as dawn broke Monday in their ongoing search for a man missing after an oil and gas platform explosion on a lake near New Orleans.
The Coast Guard was being aided by St. John and St. Charles parishes, Louisiana Wildlife and Fisheries, the City of Kenner, the Jefferson Parish East Bank Consolidated Fire Department and East Jefferson Hospital.