VINTAGE VIDEO: Ice Jam Takes Out Bridge on St. John River in Northern Maine in April 1991

As the ice breaks up on the rivers during the spring thaw in northern Maine, ice jams can build up to massive proportions. This video, shot in April 1991 on the St. John River in Allagash, shows how dangerous ice jams can be.

One minute a crowd of onlookers is standing on the bridge, laughing and carrying on, and the next minute they are all screaming and running for their lives, as the towering ice floe plows into the bridge and carries it away.

In addition to sweeping away the steel and concrete Dickey Bridge in Allagash on the evening of April 9, 1991, an ice floe also destroyed the Little Black River Bridge about a half mile away.

The aftermath of the 1991 spring flood in northern Aroostook County

There were no injuries reported but the flooding that ensued forced the evacuation of about 100 local residents. Nearly two dozen people were stranded after the bridges were swept away.

"One mobile home was crushed by the ice floe, five homes were knocked off their foundations and at least another 15 homes were flooded, authorities said. Ice boulders littered one section of Route 161 on Wednesday in an area where the river had spilled over its banks and then receded,"  The Bangor Daily News reported on April 10, 1991.

Then-Governor John McKernan declared a state of emergency that authorized the deployment of National Guard troops and other state resources to help flood victims and to clean up the flood damage.

This raw video was shot from the bridge and captures the life-threatening moment of impact when tons of river ice destroys the 720-foot-long Dickey Bridge,  bringing down power poles as frightened sightseers scramble to get out of harm's way.

[YouTube video posted by Louie Pelletier III]