With the bombing of the La Spezia factory, he moved to Lucca. Here, after 8 September, he came into contact with some anti-fascists. In particular, he collaborated with Professor Carlo Del Bianco in setting up the first armed groups. He engaged in collecting weapons, building an underground printing press and rescuing straggling soldiers and former prisoners. In January 1944, he founded and directed the local PAS; and collaborated with Leandro Puccetti's Valanga group. On 29 June, he planned an attack on the Carabinieri barracks in Borgo Giannotti. He then summoned two teams to the Teti plant in Via Santa Croce. Having ascertained the presence of German soldiers, they postponed the action and hid their weapons. However, they were intercepted by a Upi patrol. During the scuffle, Bartolozzi was wounded but managed to escape into vicolo San Quirico. He was then intercepted by two Gnr militia who machine-gunned him, robbed him and at around 10.30 p.m. left him dying in front of the Cinema Vittoria. Picked up by some citizens, he died a few hours later at Campo di Marte Hospital. He is remembered on two plaques, one in Via Santa Croce (at his workplace) and one in Via del Suffragio, near Piazzetta dell'Olivo (where he was shot).