In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.
Q: Sentence1: A construction company wanted to build a bridge over a river. Sentence2: The lead engineer wanted to try out a new technique. Sentence3: He built the bridge without using any concrete or steel. Sentence4: The bridge was held for 45 seconds without collapsing. Sentence5: All the debris blocked the river and created a dam.
A:
Company, Engineer