>> pelley: mohammad's house had been hit by a mortar, and he became unforgettable to samer attar. >> because he lost his mother and his siblings and both of his legs. the day before i left aleppo, he asked me to bring back robotic legs, prosthetic legs, if i ever returned. and if only it were that simple. he thought that i could deliver them like a pair of gym shoes, and that everything would be back to normal. he'd go back to running around and playing soccer. >> basel termanini: it's the worst humanitarian crisis on our lifetimes, and because those are our own people. >> pelley: basel termanini is vice president of the syrian- american medical society. he's a gastroenterologist in steubenville, ohio. he told us the society donated 120 ambulances, pays the salaries of nearly 2,000 syrian staff, equips 135 medical facilities and is building more. >> termanini: there have been more than 500 attacks on health care facilities. and we have more than 800 casualties from the staff. so we're trying to move all those facilities underground. >> pelley: did you say 800 medical professionals hav