Threat details

A list of details collected by potential terrorists to use in an attack against financial institutions, according to a senior official on condition of anonymity:

The flow of pedestrians outside one building -- 14 people per minute midweek on each side of the sidewalks, or 28 per minute.

Information that some explosive materials may not be hot enough to melt the steel underpinnings of a building, and a reference to what materials might heat to 2,700 degrees.

Suggestions for building reconnaissance, such as a window table at a nearby coffee shop.

Details about specific security checkpoints inside buildings, including a tidbit that people turned left after passing one checkpoint.

Places to make contact with building employees.

Locations of police stations, fire departments, schools and hospitals in the vicinity of the targets.

Changes in day-to-day security, including lessened security on Sundays and days when elevators don't operate.