This photo shows a glazed brick masonry wall of one of New York City's buildings. The moisture migrated into the brick and saturated it, then freeze-thaw cycles split the bricks, leaving its faces loose. Facade thermal movements propelled the brick outward.
The glazed faces of bricks act as a vapor barrier, which prevents moisture evaporation. Last but not least, window sills have no projections nor drip edges. Water simply runs on the facade.

The following photo shows the same condition after loose pieces were removed.

New York City building code (Local law 11) requires routine facade inspection against unsafe conditions every 5 years.