What is the meaning of the phrase "tomb-like" in the story "The Pedestrian"?

Mr. Mead, the pedestrian in Ray Bradbury’s short story, is describing the houses he passes each night on his walks around town. He describes the houses as dark “tombs” and the streets as being like graveyards as he meanders around the “dead” town. All the citizens, except for Mead, are in their homes watching television. They aren’t enjoying life but have given themselves over to the mindless entertainment provided by the 100 or more channels on television. They have metaphorically sealed themselves off from the world (like in a tomb) and are no longer “living.” Mead also comments that he sometimes sees ghostly shadows go across the walls in the houses created by the reflection of the television in the dark homes. 

Bradbury’s use of a recurring death motif through his descriptions of the homes and streets shows his fear that we are giving our lives over to technology. His predictions in the 1950s were unbelievable in how he foreshadowed the effects of television and the media in our daily lives today.