On 14 April 2012, while representing Livorno, Morosini suffered cardiac arrest and fell to the ground in the 31st minute of the Serie B match away to Pescara. He stumbled on the ground, trying to get up, before losing consciousness and receiving medical attention on the field. A defibrillator was used on Morosini, who was conscious when he was taken on the stretcher. According to the news agency ANSA, a city police car was blocking the stadium’s exit for the ambulance for nearly a minute, but a heart specialist said that the delay made no difference. After Morosini was taken to the hospital, the match was abandoned with Livorno leading 2–0, and some players reportedly “left the field in tears”. Morosini was rushed to the Santo Spirito hospital, but reports later indicated he died before reaching the hospital. Italian media reports were alerted of Morosini’s death after an “explosion of shouts and tears” by his teammates who had gone to the hospital. All of the Italian football league matches for the weekend were suspended. Livorno and Vicenza then decided they would retire the number 25, the number Morosini wore whilst their player. Morosini’s death came four weeks after Fabrice Muamba suffered a cardiac arrest in an English FA Cup match, after which awareness of heart risk had been raised in Italian football. Morosini’s sister, who is disabled, was left with no family. However, Udinese player Antonio Di Natale confirmed that he would financially support and look after her. Several days after Morosini’s death, the Curva Sud of the Stadio Atleti Azzurri d’Italia—the home stadium of Atalanta—was renamed the Curva Piermario Morosini in his honor. On the third anniversary of his death, Juventus goalkeeper Gianluigi Buffon dedicated his side’s 1–0 away win over Monaco in the 2014–15 UEFA Champions League quarter-final to Morosini. The award for the best player of Campionato Primavera is named after him.