OLYMPIA, Wash. — Voters approved Initiative 1000 on Tuesday, making Washington the second state to give terminally ill people the option of medically assisted suicide. The ballot measure, patterned after Oregon's "Death with Dignity" law, allows a terminally ill person to be prescribed lethal medication, which would be self-administered. With about 43 percent of the expected vote counted Tuesday in unofficial returns, I-1000 was being approved by a margin of about 58 percent to about 42 percent. Supporters, led publicly by Democratic former Gov. Booth Gardner, said the initiative would provide a compassionate way for terminally ill people to die.