Investigators are trying to determine the origin of grenades in a Santa Monica storage area that were transported to East L.A., where the blast occurred Friday.

The police presence comes a day after a boat docked nearby was under investigation – authorities were looking to see if that boat was in any way linked to last week's explosion in East Los Angeles that killed three members of LASD.

The investigation into the deaths of three L.A. County deputies, all killed by an explosion of military-style grenades thought to be inert, has made its way from Santa Monica to Marina del Rey where law enforcements officials were spotted outside an apartment complex Monday.

The device that exploded last week at a LASD facility and killed three detectives was a grenade, ABC News sources confirmed.

Officials are investigating a Marina Del Rey apartment complex in connection with the explosion in East Los Angeles that killed three LA County sheriff's deputies.

Alexis Westland dropped her GoPro below the surface of Marina del Rey in Los Angeles to record footage from the bottom of the Pacific Ocean.

A waterfront housing community in Southern California’s Marina Del Rey has traded hands, the neighborhood’s first waterfront multifamily property to sell in the post-COVID era.