crashed through the side wall of a highway bridge and plunged into a ravine
Rescuers wielding electric saws cut through the twisted wreckage of the bus looking for survivors overnight
and state radio quoted a local police chief as saying the bus driver was among the dead
The bus lost control near the town of Monteforte Irpino in Irpinia
a largely agricultural area about 60 kilometers (40 miles) inland from Naples and about 250 kilometers (160 miles) south of Rome
hitting several cars before plunging some 30 meters (100 feet) off a viaduct on Sunday night
It was not immediately clear why the bus driver lost control of the vehicle
but prosecutors were investigating technical problems and had ordered an autopsy on the driver
Italy's Prime Minister Enrico Letta described the crash as a "dramatic moment" for his entire country
"We are deeply pained by this tragedy that has touched many families and many children," Letta said from Athens
where he met with Greek Prime Minister Antonis Samaras
told Sky TG24 TV from the scene that some witnesses told him the bus had been going at a "normal" speed on the downhill stretch of the highway when it suddenly veered and started hitting cars
Some witnesses thought they heard a noise as if the bus had blown a tire
"All possible causes are under examination
It could be a combination of causes," Avellino Highway Police Chief Salvatore Imparato said on Sky TG24
The bus was carrying a group of weekend holidaymakers from the town of Pozzuoli
The group had arrived at a hotel on Friday afternoon
and had spent the weekend visiting the spa and an early home of Padre Pio
a late mystic monk popular among Catholics
Relatives visited a makeshift morgue in a middle school to identify the dead on Monday
was towed from the site to be examined for possible malfunctions
Firefighters extracted 37 bodies from the wreckage
Most of the dead were found inside the mangled bus
while a few of the victims were pulled out from underneath the wreckage
state radio and the Italian news agency ANSA reported
Cars that were hit by the bus stood on the highway
It was not immediately known if anyone in those cars had been injured
Salvatore Laporta and Gregorio Borgia contributed to this report from Monteforte Irpino
EARLIER: A tour bus filled with Italians returning home after an excursion plunged off a highway into a ravine in southern Italy on Sunday night after it had smashed into several cars that were slowed by heavy traffic
had warned of slowed traffic ahead along a stretch of the A116 autostrada
appeared to have lost control of his vehicle
firefighters said that they had extracted 37 bodies — most of the dead were found inside the mangled bus
state radio and the Italian news agency ANSA reported.
The radio report said 11 people were hospitalized with injuries
It was not immediately known if there were other survivors or any missing
Rescuers wielding electric saws cut through the twisted metal to better probe the interior of the bus
stopping occasionally in silence to listen for any cries for help
even as the bodies were put into coffins to be taken to a morgue
Reports said as many as 49 people had been aboard the bus when it ripped through a guardrail after slamming into several cars
then plunged some 30 meters (100 feet) off the highway and into a ravine near a wooded area
the bus tore away whole sections of concrete barriers as well as guardrail
The concrete lay in large chunks in a clearing in a wooded area where the bus landed
State radio quoted Avellino police as saying the bus driver was among the dead
Occupants of cars which were hit by the bus stood on the highway near their vehicles
The highway links western and eastern Italy across the south
Early reports said the passengers had spent the day in Puglia
an area near the Adriatic on the east coast famed for religious shrines
a state radio reporter at the scene said authorities told him that the bus had been bringing the passengers home after an outing to a thermal spa area near Benevento
Others at the scene said the passengers might have visited a town near Benevento that was the early home of Padre Pio
a late mystic monk highly popular among Catholics in Italy
Passengers came from small towns near Naples
The bus dove off the highway near the town of Monteforte Irpino in Irpinia
a largely agricultural area about 40 miles (60 kilometers) inland from Naples and about 250 kilometers (160 miles) south of Rome
He said some witnesses thought they heard a noise as if the bus had blown a tire
A local prosecutor arrived at the crash scene to begin an investigation into the cause of the crash
Photographer Salvatore Laporta contributed to this report