The U.S. military's recently released report on the bombing of the Doctors Without Borders (Medecins Sans Frontières) hospital in Kunduz in October blames human and technical errors. However, it remains somewhat unclear why the attack continued even after MSF phone calls to Bagram air base reporting that the hospital was being shelled.
By coincidence, I recently ran across a reference to an attack by coalition forces in February 1991 during the Gulf War on an air-raid shelter in Baghdad, killing (according to news accounts at the time) two or three hundred civilians. In that case the U.S. apparently thought the shelter was reserved for Iraqi government leaders; a Human Rights Watch report released after the war argued the U.S. was legally obligated to have warned "the Iraqi civilian population that the facility
was no longer considered a protected shelter and provided sufficient time
to elapse so that [the] warning could be heeded" (see here - scroll down to the section headed "The Lack of Warning Prior to Attack: The Ameriyya Air Raid Shelter"). Not a precisely comparable situation, but similar inasmuch as misinformation/misidentification apparently played a role. (I'm sure the attack on the Baghdad shelter has been discussed in other places, but I'm not taking the time to research it any further right now.)