A fuel depot north of London is still burning after huge explosions ripped through it shortly after dawn Sunday, injuring 43 people. Authorities say all indications are that the explosions were accidental, but an investigation is underway. Nearby residents have been evacuated and other have been told to stay indoors to avoid smoke from the burning fuel. Environmental experts say it does not appear that the smoke will be an immediate danger to the general public. The fire is not expected to be extinguished until Monday at the earliest. The depot is owned by Total, a French subsidiary of Chevron Texaco, and supplies fuel and heating oil to much of southeast England, including Heathrow and Luton airports.