For the third-straight day, investigations into last week's deadly explosion at a Los Angeles County Sheriff's Department training facility were centered in Marina del Rey on Wednesday.

Authorities from several agencies assisted the LASD throughout the day on Tuesday in their investigation, including the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Los Angeles Police Department. The investigations continued into Wednesday, LASD confirmed, focusing on a storage unit located in Dell Alley, which is behind an apartment complex and is near the Marina.

Residents of the apartment complex told CBS News Los Angeles that they received a notice on Tuesday asking that they avoid balconies and windows. They said that the storage units aren't tied to the building, and some former tenants still store items inside.

"For them to be here for as long as they've been here lets me know that there's something of interest that was in that locker," said Dante Johnson, a building tenant.

The LASD has confirmed that investigators are following leads that are connected to at least one grenade-like device found by its bomb squad inside a Santa Monica garage along the 800 block of Bay Street the day before the explosion. Authorities believe an explosive recovered that night is possibly what caused the blast.

The explosion killed three highly trained detectives with LASD at the Biscailuz Training Facility in East L.A. just before 7:30 a.m. Friday. They were identified as Joshua Kelley-Eklund, Victor Lemus and William Osborn. Authorities say the men were working to render an explosive safe when it exploded.

"There's a lot more that we don't know than we do know," Sheriff Robert Luna said last Friday, adding that it was too early to say what the deputies were doing when the blast took place. "But our intent is to look at this from the very beginning and figure out what is it exactly that caused this tragic event." 

As of Wednesday, authorities haven't officially named a suspect connected to the events or announced any arrests.