Cradle Robber by John Watson

Buried in the depths of Echo Park Lake for a half-century, the Aswang goes free when a major earthquake plunges the city of Los Angeles into darkness. Hungry for blood, the creature heads for the nearby maternity hospital, where emergency generators have the facility barely clinging to power. As the power fails and the night grows darker, families fight to spare their children from the grasp of the cradle robber.