Even when walking in a large group, city streets should be considered unsafe after dark.

She'd lived in parts of Chicago, near the university, that were considered frankly unsafe.

The area is generally considered unsafe after dark due to lack of lighting and road access.

More than 200 parts per million is considered unsafe.

The attacks were so frequent that the neighborhood was considered unsafe for several years.

Anything above that figure is considered unsafe by international health experts.

Although used in climbing, the water knot is considered unsafe.

A falling branch had killed a young girl and so the trees were considered unsafe.

In 1999 they had to tear down this school full of many memories because it was considered unsafe.

Of 1,518 children from the community tested in recent weeks by public health officials, 92 percent had lead levels that were considered unsafe.