We present here the current prototype of the text understanding system HELENE. The objective of this system is to achieve a deep understanding of small reports dealing with a restricted domain. Sentence understanding builds a model of the state of the world described, through the application of several knowledge modules: (i) LFG parsing, (ii) syntactic disambiguation based on lexical entry semantic components, (iii) assembly of semantic components and instantiation of domain entities, and (iv) construction of a world model through activation of common sense and domain knowledge.