These angels do not look like angels. They look like old people, stooped and weary, clothed in the rags they have been wearing for centuries.
From a distance it almost appears that they are hanging their heads, but in actuality they are looking down, as they so often do, situated as they are at such a lofty remove from the old torments and joys of the earth.
They are standing together, huddled and peering down over the lip of a cloud, watching a bridge burning far below them.
A burning bridge is one of the half dozen earthly occurrences (along with the suffering of children, cruelty to animals, neglect of the elderly, joylessness, and acts of religious bigotry and intolerance) that are capable of breaking even the hearts of angels.
A bridge --all bridges-- are essential symbols of the mission of angels, and the destruction of bridges is a tragedy that reverberates through the most distant and rarefied reaches of Heaven.
A burning bridge is even more tragic and lamented than a bridge obliterated through mere destruction or disaster. It is also, sadly, one of the few acts of human willfulness in which the angels are not allowed to intercede. The burning of bridges is an act of terrorism against hope, and reduces even the oldest angels to a pack of numb and speechless spectators at the scene of a disaster.