shock waves as pope francis weighs into the race for president. why he said donald trump is not a christian. donald firing back. >>> it's getting ugly as rubio and cruz have accusations. >>> sudden impact. a terrifying chopper crash caught on tape near pearl harbor. breaking news from hawaii. >>> a hospital hacked. its computers frozen, forced to pay ransom to gain back control. and a warning it could happen to you. >>> and hidden risk. when even exercise won't lower the stubbornly high cholesterol. what doctors say you need to get rid of to bring it down. "nightly news" begins right now. >>> from nbc news world headquarters in new york, this is "nbc nightly news" with lester holt. >>> good evening. it's virtually unheard a u.s. presidential candidate, in this case [ bleep ]donald trump over his immigration plan. pope francis returning home took the reporter's question about trump's pledge to build a border wall. in his answer, implied that trump is not a christian. it was a high-level rebuke to say the least. but true to form, trump is not turnin

as he does on nearly every foreign trip, francis visited a prison. one of the inmate musicians overwhelmed. this evening's mass broadcast on both sides of the border. >> religion reaches over walls, over mountains. >> reporter: the joy on the pope's face marred only by a brief flafsh anger when an overzealous fan almost pulled him down on to a person in a wheelchair. don't be selfish, he said. the vatican says mass here on the border is not a political statement but a moral one by a pastor trying to unite a divided >> anne thompson tonight in mexico can, thanks. >>> it's being called a landmark study that could affect millions of men who suffered from low testosterone. low-t as ads call it have been linked to everything from plos of energy, muscle mass and sexual function to increased vulnerability to illness and now as nbc's tom costello tells us new research sponsored by the national institute of health toys testosterone replacement therapy may have benefits. >> i figured low testosterone would decrease my sex drive. >> reporter: a $5 bill yo a yea

border fence pope francis builds a symbolic bridge from mexico on immigration. francis himself the son of immigrants seeking to put a human face on the people fleeing what he calls grave injustices, poverty, exploitation and violence. among the hundreds of thousands jasmine flores who crosses the border every day to go to school. >> for him just to cam to juarez, means everything to us. >> reporter: no longer the murder capital of the world juarez is still a dangerous place. father half jer kovalio runs a shelter for immigrants. he says he hopes francis can make americans see the people he helps every day should be treated with dignity. as he does on nearly every foreign trip, francis visited a prison. overwhelmed. this evening's mass broadcast on both sides of the border. over mountains. >> reporter: the joy on the pope's face marred only by a brief flafsh anger when an overzealous fan almost pulled wheelchair. don't be selfish, he said. the vatican says mass here on statement but a moral one by a pastor trying to unite a divided world. lester. >> anne thompson

keir simmons, nbc news, damascusus >>> thousand flocked to see pope francis today at a stadium in mexico's poorest state. he met with families at the e ent which llowed annenorm open-a-a mass t tt he presided over earlier. and a moving moment from his visit yesterday to a children's hospital sang "ava maria" for him earning a kiss from the pope and bringigi those around him to tears. >>> still ahead here tonight, another new warning about common artburn medications. why the millionssf americans who take them could be at risk of m mory lossss >>> a ao, t t dangerous mid-air . . >>> we're back now with the new concerns about the prescription meds that so many people take to treat heartbeat and ascid reflux. 15 million americans take them toolock stomach acid and researchers sugugsted last weekkhat the medications may bebe linked to kids kidney fractures. now another concern being raised, that there is a link to dementia. nbc's tom costello has the information you should hear. >> reporter: 34-year-old tara h h acid reflux so bad it made her job as s speech therapist nearly impossible. >> i ac

. >>> thousand flocked to see pope francis today at a stadium in mexico's poorest state. he met witit families at t t event which fofoowed an enorm presided over earlier. and a moving moment from his visit sterday to a children's hospital when a teenage patient sang "ava maria" for him earnini a kiss from t t pope and bringing those arororo him to tears. >>> still ahead here toninit, another warning about common heartburn medications. why the millionon of americics who take them could be at risk of memory loss. >>> also, the dangerous mid-air incident that shook up oneef the pilots aboard an guys, it's just the two of you. the setting is just righgh ththe's something in the air. but hehe's'she thing: about half of men over 40 have some degree of erececle dysfunction. well, , agra helps guys with ed get and keep an erection. ask your doctor r your heart is healthy enough for sex. do not take viagra if you take nitrates for chest pain or adempas for pulmonary hypepepesion yoururlood pressure could drdr to an unsafe level. to avoid long-term injury, seekk immediate medical h

he says he wants to meet the pope because he believes francis can give the parents rength. such high expectations stretch from mexico city to chicago's immaculate conception parish where 95% are mexican origin. i hehe, is the pope a ghost? he is not god. he is not going to change things immediately. over time. >> reporter: the nation of many problems and a deep faith. next week, the pope turns his attention to e issue of immigration travelingng to the south where many central american immigrants enter this country and then to thth norththo say mass at the u.s. border.. erica? >>> fuel on dema (vo) what's your dog foooos first ingredient? corn? wheat? in purina one true instinct grain free, real chicken is always #1. no corn, wheat or soy. support your active dog's whole body health >>> while low gas prices are making a ip to the gas station a lot less painful, it't' not just the prices making itt easier to fill up the tank. >> reporter: the purple truck i ihard to miss. its service difficult to pass up. >> how would you like it if you don't have to ever go to thee gas stati

when we come back, surf's up, way up. 50-foot waves the wowod's most >>> history in cuba today as pope francis arrived on the island ahead of a trip to mexico. there he met with the head of the russian orthodod church, kissing each other on the cheeks and embracing at the havana airport, a major step towards bridging a schism that's divided christianity for a thousand years. >>> it's onenef the most dangerous surfing eventsts in the world d this year's titans of mavericks competition in northern california is living up to its reputation with 50-foot waves supercharged by el nino, barreling in at 40 miles per hour just 15 seconds apart. 24 of the world's elite surfers are competing for a $120,000 prize and bragging rights. why this whole kindergarten class is already collele daughter: calls me googly eyes. mom: you know you're beautiful right, you know that? daughter: even you're beautiful. i got bullied for wearing glasses. share if you're against bullying. mom: we put it out there, it just took off. 3 million people have shared this post. don't let bullies get you down, i stand with you. that

. >>> history in cuba today as pope francis arrived on the island aheaea of a trip to mexico. therer he met with the head of the russian orthodox church, kissing each other on the cheeks and embracing at the havana airport, a

. >>> history in cuba today as pope francis arrived on the island aheaea of a trip to mexico. therer he met with the head of the russian orthodox church, kissing each other on the cheeks and embracing at the havana airport, a major step towarar bridging a schism that's divided christianity for a thousand years. >>> it's one of the most dangerous surfing events in the world and this year's titits of mavericks competition in northern california is living up to its reputataon with 50-foot waves susurcharged by el 40 miles per hour just 1515econdsdsapart. 24 of the world's elite surfers are competing for a $120,000 prize and bragging rights. >>> when we come back, why thihi whole kindergarten class is already college bound. a these little guyuy they represent blood cells. and if you have afib-an irregular heartbeat that may put you at five times greater risk of stroke they can pool together in the heart, forming a clot that c c break free and travel upstream to the brain, where it can block blood flow and cause a stroke. but if you have afib that's not caused by a heart t lve prob