The strength, sophistication and timing of the Saturday morning attack shocked Israelis. Hamas fighters used explosives to break through the border fence enclosing Gaza, then crossed with motorcycles, pickup trucks, paragliders and speed boats on the coast.In some towns, a trail of civilians’ bodies lay where they had encountered the advancing gunmen. On the road outside the town of Sderot, a bloodied woman slumped dead in the seat of her car. At least nine people gunned down at a bus shelter in the town were laid out on stretchers on the street, their bags still on the curb nearby.