Families on base have rallied around the service members of both the McCain and the Fitzgerald, the destroyer that crashed in June, collecting clothes, toiletries and old uniforms for crew members who probably lost everything when their berths were flooded after the collisions.

The McCain is currently docked at the Changi Naval Base in Singapore. Lt. Paul Newell, a spokesman for the Seventh Fleet in Yokosuka, said he was not sure whether or when there would be a memorial service at the base for the fallen.

“Everybody is heartbroken,” said Tara Oberdorf, whose husband serves on the Ronald Reagan, which recently returned to port after six months at sea.

Mrs. Oberdorf, who was finishing back-to-school errands on Thursday afternoon with three of her four children in a busy shopping arcade near the base, said it was difficult not to be troubled by the number of recent accidents. “So now you just worry and ask, why?” she said.

Among the questions being asked are whether the crews on either the Fitzgerald or the McCain were overworked and underprepared. Given the current geopolitical situation, many of the ships in the fleet are sent out on frequent missions, with some naval experts raising the question of whether crews have enough time to rest or retrain.

“Are ships deployed a lot? The answer is yes,” said Cmdr. Clayton Doss, a Seventh Fleet spokesman. “Our Navy is deployed a lot globally.”

At a fruit and vegetable shop near the train station in Yokosuka, the wife of another Ronald Reagan crew member said that “all military bases are overworked.”