As I reported earlier this week, an out-of-control 19,000-pound Chinese space station--Tiangong-1, or Heavenly Palace-1 in English--is expected to crash to the earth in just a few days, potentially wreaking havoc if it falls on a major city.

Unfortunately, according to scientists, many major cities are now directly in the path of the wayward spacecraft, including San Francisco, New York, Miami, Los Angeles, Madrid, Beijing, Tokyo, New Delhi, Rio de Janeiro, Sydney, and others.

While scientists still don't know exactly when the space station will come crashing down onto the earth, they now predict that it will occur in just a few days, sometime between March 30 and April 2. Chinese mission control engineers say they don't know exactly where the space station will crash. According to one Chinese official, "It is impossible to name the exact re-entry location at this stage."

Scientists now say that the reentry of Tiangong-1 is likely to trigger a spectacular series of fireballs which would be visible even in broad daylight.

While much of the spacecraft will likely burn up on reentry into the atmosphere, many large pieces of metal and other materials--some more than 200 pounds each--are expected to survive and hit the surface of the earth at a very high velocity with potentially tragic consequences.

In addition, Aerospace Corporation issued the following urgent warning to anyone who encounters debris from the space station:

"Potentially, there may be a highly toxic and corrosive substance called hydrazine on board the spacecraft that could survive reentry. For your safety, do not touch any debris you may find on the ground or inhale vapors it may emit."

As Tiangong-1 nears its date with destiny, scientists should have better information as to exactly when the space station will crash. Until then, for those in the danger zone, it would be a good idea to stay alert to breaking news.