A person takes photos after the explosion on a gas platform in Lake Pontchartrain where seven people were rushed to hospital, with five in critical condition, and one person is still missing in Kenner, La. Monday, Oct. 16, 2017.

Investigators searching the Clovelly Oil Co. platform in Lake Pontchartrain that exploded Sunday night did not find the body of missing worker Timothy Morrison, but Jefferson Parish Sheriff Joe Lopinto said a helicopter is still searching the area daily.

Rescue workers got onto the platform late Tuesday to search the wreckage from the explosion and resulting fire, which occurred during a routine cleaning of oil and gas lines leading to the storage platform 1½ miles off the Kenner shoreline.

The explosion sent seven workers from Clovelly and at least one subcontractor to local hospitals. Two of them — Alvin Kimbrel of Belle Chasse and Lawrence Dufrene of Marrero — remain at a burn unit at Baton Rouge General Medical Center. It was not clear Thursday if James Bordelon of LaPlace remains hospitalized.

A memorial for Morrison, who lived in Katy, Texas, is planned Sunday in Texas.

Lopinto said it will be a couple of days before divers can be added to the search efforts in the lake. The water is only 12-15 feet deep, and high winds earlier in the week kicked up sediment from the bottom that still hasn’t settled, he said.

The U.S. Coast Guard called off its search on Tuesday night but continues to monitor for signs of environmental impact, which thus far has been nonexistent.

The company said the three oil-carrying lines leading into the platform had been shut down before the explosion, and a fourth — which carried natural gas — was closed after the explosion and flared off the following day.

The Occupational Safety and Health Administration has since joined the investigation of the explosion.

The Coast Guard, Kenner police and Clovelly-hired contractors have been sweeping the shoreline for debris. Any oil samples found will be tested to see whether they are a result of the explosion and fire, officials said.

Kenner officials said Clovelly hired the Center for Toxicology and Environmental Health to monitor the air in Kenner neighborhoods and found “crude oil and natural gas-associated compounds and combustion products were not present at levels that would pose a health concern.”

Rescue and recovery operations based at the Kenner boat launch were scaled back enough to reopen the site for general use Thursday afternoon.

“Caution is still advised as shoreline oil and debris identification is ongoing as is clean-up of the oil platform,” the city said. “The public may enjoy the area, but proceed with caution given the circumstances.”

Follow Chad Calder on Twitter, @Chad_Calder.