It happened 80 years ago today.
Rhine River, Worms, Germany, U.S. Seventh Army area of operations. The official caption to period original Kodachrome: “U.S. Army mechanized forces cross the Rhine River on the Alexander Patch Heavy Pontoon Bridge, 28 March 1945. The bridge, built by the 85th Engineers, replaces the ruined bridge at right, which was destroyed by the retreating German Army.”
The 85th Engineer Heavy Pontoon Battalion was activated on 3 June 1941– six months before the attack on Pearl Harbor- at Ft. Belvoir, Virginia, just one of 12 such units established by the Army in WWII. Its cadre was drawn from the 5th Engineer Regiment(Combat).
Each Heavy Pontoon Battalion was made up of 16 officers, 3 warrant officers, and 501 enlisted men and, as the name would imply, specialized in erecting the M1940 series heavy pontoon bridge capable of holding up to 26 tons as opposed to light (10 ton) and pnuematic raft (5 ton) types through the use of Mack trucks and assault boats.

Another view of the Worms bridge with a tank destroyer rattling over it on 26 March, before the sign was erected. Not the kind of stuff you can handle just any pontoon.
Shipping out to North Africa in May 1943, the 85th landed in Italy shortly after to support 5th Army and then shipped out for France in 1944 and switched to the 7th.
The Battalion earned five battle stars for participation in the following battles and campaigns: Naples-Foggia; Rome-Arno; Southern France; Rhineland; and Central Europe.
Their motto was “No River Too Swift.”