81.   The cause of the crash was not immediately known, but there was thick fog in the area.

82.   The fog is likely to last all month, according to city meteorologists.

83.   The fog was likely to continue for two more days, the weather office said.

84.   The fog was so thick that rescuers had trouble seeing one another on the trek to the site, he added.

85.   The early morning was clear but dense fog was in the interior of Puerto Rico with considerable haze on the coasts.

86.   The fog was too thick.

87.   There was fog at the time the bus left the road, but the cause of the accident has not been determined.

88.   There was fog in the interior valleys.

89.   There was dense fog at the airport when the near-accident occurred.

90.   There was fog in the interior part of Puerto Rico.