Honolulu vehicular homicide investigators are looking for one vehicle — and possibly others — that hit and killed a 21-year-old Navy sailor walking on the H-1 freeway and then fled the scene early yesterday morning.

Later in the day, a fatal mo-ped crash involving a visitor from Washington state closed Kalanianaole Highway near Makapuu.

In the early morning fatal accident, a 2007 Nissan Altima driven by a 22-year-old Mililani man also hit the sailor but did stop and called police at about 2:17 a.m., police said.

Investigators are still trying to determine why the sailor was walking in the westbound lanes of the H-1 just before the Makakilo offramp.

They don’t know whether drugs or alcohol were involved.

The sailor was hit by one vehicle that fled the scene and possibly by another vehicle, police said. He was pronounced dead at the scene.

The collision temporarily forced the closure of the H-1 freeway near Makakilo.

At Makapuu a 59-year-old Tacoma, Wash., man was riding a mo-ped with two others on mo-peds when he lost control in the Makapuu-bound lane of Kalanianaole Highway at about 12:45 p.m. His vehicle started to wobble and veered into an oncoming lane, police said.

A Toyota Tundra pickup, driven by a 40-year-old Honolulu man in the Kahuku-bound lane, hit the mo-ped driver as he fell to the ground, police said.

A woman on one of the other mo-peds crashed while she was watching the man get hit, but she was not seriously injured.

The Washington man was taken in critical condition with head and internal injuries to Castle Medical Center, where he died, police said. He was not wearing a helmet.

Police closed both directions of Kalanianaole between Makai Pier and the Hawaii Kai Golf Course. The road was reopened just before 3:30 p.m.

The two deaths brought Oahu’s traffic fatalities to 11 this year compared with 13 at this time last year.