Rescuers are searching through collapsed buildings in western Colombia for survivors after the country’s strongest earthquake this century killed at least 250 people and caused widespread devastation, according to local authorities.Emergency teams in the worst affected cities, including Cali and Pereira, have been working through the night and into Tuesday, listening for signs of life and trying to reach people trapped beneath concrete and debris during the magnitude 7.4 earthquake. The Choco region west of Cali and Pereira has also been impacted, but the extent of the damage is still not clear.Authorities have warned that the death toll from Monday’s…