The Boston Fire Department responded to a Level 3 hazmat situation on Wednesday evening after an ammonia leak was reported at a seafood warehouse, according to authorities.

Firefighters responded at about 6 p.m. to the reported leak at the Stavis Seafoods Warehouse on Channel Street, according to NECN.

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Fire officials were initially unable to enter the site to shut off the ammonia because in order to make entry they had to be wearing full-encapsulated suits, the Boston Fire Department tweeted.

As of 8:15 p.m. the fire department was able to make two entries into the location, during which the body of one worker was recovered on the second floor. Firefighters attempted to get to the worker — who inside for abotu an hour — during the first entry but were pushed back by the ammonia, according to John Walsh, Chief of Operations for the Boston Fire Department. 

Walsh added that the ammonia was still flowing and officials are trying to get to a valve on the pipeline where the ammonia flows, which is usually easily accessible, but they have not been able to get to it. A total of about 5,300 pounds of ammonia are stored in tanks within the site. 

"We're going to be here a while," Walsh said Wednesday night. 

Boston Fire added that when two firefighters entered the location, an equal number of personnel must be outside read to go in at once, NECN reported.

Police said they have shut down several streets surrounding the city’s Seaport District,specifically towrads Summer Street, and motorists are advised to find alternate routes.

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The Boston Fire Department also tweeted that the time of the leak was also the end of the shift for workers at the facility and an investigation behind what caused the leak is still ongoing and will be conducted by fire investigators, Boston police and the Suffolk District Attorney's office. 

There were about five to six people in the faciity during the time of the leak, and workers are being evaluated my emergency personnel. 

The cause of death of the worker found inside the warehouse will be determined by the Office of Chief Medical Examiner.