GUATEMALA CITY — A bus veered off a highway bridge into a polluted ravine in Guatemala City early on Monday, killing at least 51 people and trapping survivors, a spokesperson for the city’s fire department said.

The densely packed bus was traveling into the capital from the town of San Agustin Acasaguastlan on a busy route into the city from when it plunged approximately 20 meters from Puente Belice, a highway bridge that crosses over a road and creek.

The spokesman, Carlos Hernández, said the bodies of 36 men and 15 women had been sent to a provincial morgue set up for the accident.

Images shared by the fire department on social media showed the bus partially submerged in wastewater surrounded by victims’ bodies.

Guatemalan President Bernardo Arévalo declared three days of national mourning and deployed the country’s army and disaster agency to assist in response efforts.

“I stand in solidarity with the families of the victims who today woke up to heartbreaking news. Their pain is my pain,” Arévalo said on social media.