The Baltimore bridge had Thermite charges along the top and possible bottom.
“Thermite is a pyrotechnic composition of a metal powder and a metal oxide that produces an exothermic oxidation-reduction reaction known as a thermite reaction.Most varieties are not explosive, but can create short bursts of extremely high temperatures focused on a very small area for a short period of time. The thermite is simply a mixture of metal, often called the “fuel” and an oxidizer. “
