At least 51 people are dead after their bus plunged off a bridge Monday on the outskirts of Guatemala’s capital, said Hector Flores, who was helping coordinate the municipal government’s response.

Firefighting spokesman Edwin Villagran said a multi-vehicle crash sent the bus off the bridge before dawn. Others were seriously injured.

The bus fell 115 feet (35 meters) into a sewage-polluted stream. It landed upside down and half-submerged.

The bus had come from Progreso, northeast of the capital. Volunteer firefighting spokesman Óscar Sánchez said children were among the victims.

President Bernardo Arévalo offered his condolences and declared a day of national mourning.

(AP)