CAMPBELL RIVER, British Columbia (AP) _ Witnesses watched in horror as a plane crashed and exploded shortly after taking off from the Campbell River airport on Vancouver Island. Authorities said all three Americans aboard were killed in Sunday's crash.

Identities of the two men and woman remained unknown Monday.

Onlookers said the twin-engine aircraft had just taken off for Bellingham, Wash., when it tried to land on a logging road about a half-mile from the airport. Instead, it struck the ground with its tail first and exploded.

''The plane wasn't climbing and it just stayed straight and wasn't gaining any altitude,'' said witness Stefan Isaacson, an airport baggage handler. ''Then it started to veer off to the right and crash in the bush and explode.''

''It's kind of a hard thing to see, especially when you have just finished talking to the pilot who died in it.''

Air BC ramp supervisor Cam Croin said he saw the three on board the plane just before they took off.

''They passed by us and made a funny comment,'' he said.

Campbell River RCMP, the Canadian Aviation Safety Board and the coroner's office were investigating.

Campbell River is about 130 miles northwest of Victoria.